After I assaulted Dragonreach with the rest of the Stormcloaks my house is no longer open. All my items and wife are in there. This has ruined the game for me.

I haven't bought that house. But perhaps waiting some time should reset things to normal? I haven't done the siege yet because I am afraid my game will get buggy and I am not playing until the next patch.

Try restarting the game. Shut off the Xbox and start it up.

I left the key in breezehome and after the siege its permanently locked for me.

Why would anyone leave keys down? They weigh nothing, are in a seperate menu so they dont clog up your inventory, and are required for entry to specific locations.

Sorry but if you left a key down inside the location and it locks you out, thats your own dumb fault.

How is that a player issue..?
The game, for nearly all locations keeps those locations open after it has been opened with a key. (Specifically the locations)
I have a feeling this same issue is also what causes the problems for the OP.

Though it might not be logical for you to keep keys away from your inventory.. It still is a choice which is available to the gamer. They might not like the keys tab etc. etc.
Nowhere in the game is the player warned about the fact that breezerhome will be re-locked again..
So no.. it's not the players fault. It is a broken mechanic or a bug. (the house is probably re-locked to avoid issues with the slightly altered state of Whiterun)
Btw:
The same is true for your house in Sollitude.. (and I might imagine Windhelm if you were able to get it)

Indeed. Some players like a clear inventory regardless of said items having 0 weight.

Sorry, but this is no one's "dumb fault" apart from the developer's.

Thanks for the heads up OP... I'm in the middle of assaulting Whiterun so I will see if my Breezehome is also locked afterwards... I have all of my materials and ingredients in there.

I still have access to my houses after the assaults (tough not while I was assaulting) in both whiterun and solitude. But I do keep all my keys on my character however. Have you tried leaving town, resting and then come back to it to see if it was open? I don't remember it requiring to be unlocked afterwards however, in my case anyway.

I just had to talk to the new Jarl, be rethaned and bam got back in. And no i didn't have to re-buy. Maybe I just was lucky but that's my story.

I've bought the houses early in the game and later in the game, didn't have any effect on being able to buy the houses, save you have to do the blood on the ice mission early in the game to keep it from becoming broken for both parts 1 & 2 (if you choose to do 2). I've done the storm cloak siege on whiterun multiple times without issue yet far as anything being able to access anything aftwards.

lol ouch, that svcks. Best place to leave any keys if you dont want to carry them all, is with Sven or that anoying elf that attacks you if you sneak attack bandits... at riverwood. I use them as 'accessable' storage outside of homes.

There's one mission where you may / may not get your keys back. its a glitch, happens with your gear sometimes too, but this isn't it, thalmar embassy is the one that does it. if I lose all my keys I just load to a previous save, to keep from losing my gear, i just stick everything in my house, give my follower all my keys and the gear i want to use in the embassy, then after getting past the gate guard in there, I wait for my follower to show up and take everything back off them. works great, and best of all no lost gear. (side note for anyone who thinks they lost gear - check the secret room in the inn at riverwood both trunks, you might be suprised to find it there even if the thalmar took it. sometimes it shows up, sometimes it doesn't). Far as this mission in question, the siege, you dont have to ditch anything to complete it.

how is that a player issue? obviously you've never locked your keys in your house. you can't very well go "hey door i already opened you with my key unlock yourself" now can you? yes locking your key inside your own house is a player issue. That one is pretty much a given, unlike the one where you need at least 1 piece of the thieves armor later on in the game with no clue that you do. Anyone should realize that locking their keys in their house is going to make it so they can't get back in, well with the exception to agoraphobics that never leave their home.

Now they could of been a little nicer about it by having your house carl leave the house once a day and wander the streets for a hour or two, being they carry a key to your houses. Or let you re-buy a key from the steward. But this is not a broken mechanic or a bug, its a oversight and thats it, nothing more.

Ok.. call it an oversight.. However since it's context based ,your house, once purchased... never locks except when doing the siege quests. Only respawning containers and NPC houses/stores relock, but are pickable.
Like I stated, there is a logical reason for this. The Quest, for obvious (scripting) reasons, doesn't allow you to enter your house during the quest. (probably it's a different cell which is being "rebuild" and saved for placement in the new Whiterun)
The fact that the house remains locked after the siege is a script issue and therefore can very well be also labeled as a bug or glitch.
Whatever you call it however.. It is not the players fault. This isn't real life.. This is a game.. A game in which players, based on their experiences in Fall Out 3 and Oblivion, can rightfully expect their houses to remain open.
The fact that people put real life logic on what a player does or doesn't do in a game and call them stupid or dumb because of that choice is simply arrogant. Whether you call it an oversight or a bug. The fact remains that the player encounters an justifiably unexpected issue which takes away their enjoyment of the game.

This just reminds me of people who go on for ever trying to blame everyone else rather than admit fault when they lock their keys in their car.
I used to know a guy whose wife locked her key in her (sometimes running) car regularly.
It was always the fault of someone else, she would never admit being to blame.

Like I said in my previous post ... this isn't real life.. It is a game in which people can expect their houses to remain open.
Applying real life logic to a simulated game world does not make a valid argument.

If my real life house door locked me out by itself without a key I'd blame the locksmith. If I manually set the latch to lock automatically on my exit that would indeed be my fault.

but had you always left the key in their and still been able to enter breezehome onother occasions ? If yes, then that is unfair for it to change now.

personally I never drop my keys, like someone said they weigh nothing I havent even thought about doing it but I regularly organise the rest of my inventory

I can be a vbit of a hoarder though, I only just after 200 hours cleared about my books section of all the journals and notes gained from questing throughout the entire 200 hours, I must have had over 80 of them