after turning off the flood lights, i wanted to back into haven to get all the loot but it tells me the door is locked and cant be picked. i have ashur's key with me though. how do i go back in?

I believe once you leave Haven and you took the child with you it bars the character from entering again. The only way you can re-enter Haven after you have left is if you sided with Ashur.

well thats just swell

if ur still there..after they took all my items at the gate i decided to load the game again and put all my stuff in trash bin nearby. i ddint realize this dlc would take so long. would all my stuff be there when i escape? im ok with restarting the whole quest but something iits wanna know before i finsih

I wouldn't because I'm not sure if that trash can respawns or not. The best thing to do is to get a player home either in Megaton or Tenpenny Tower and store a majority of your things there. Then fast travel to the Pitt then head off to the gate, that is the best thing I can tell you. I don't want to tell you to store your stuff in the trash can only for you to find out that it respawned and you lose all your stuff.