Just finished Lonesome Road. What happened at the end really pisses me off with video games: You Can NOT ever go back!

I lost about 1500 pounds of "stuff" because I thought taking it with me, thus being encumbered and slow, I stashed it all just outside Ulysses Temple. Well, after 5 tries killing Ulysses, I finally get him (and addicted to drugs in the process), I want to head out, gather my loot and use the Doctor Machine out there. But NOOOooooo... I get the "end of the story" scenario and ported back outside to The Mojave. Well... [expletive!] [expletive!] [expletive!] and [expletive!][expletive!]!!!

I HATE when games do this to me. No warning. No "heads up." Just, "Screw you!" Now, is it worth my time to try and go back with all my crap in tow, or just write it all off? How many more times will it take to defeat Ulysses this next time? (I am a pretty poor player )

I think I'll take a break from New Vegas for a bit and cool off

I usually use the Hopeville armory as a "base camp" in Lonesome Road and dump all of my excess loot in the containers inside. It's close to the start, which makes it easy to retrieve my stuff after finishing the DLC.

I'm not sure if you can fast travel from the entry of the DLC to a spot near Ulysses' Temple, but it might be worth a try so you can go back and get your stuff without dealing with too many respawning mobs.

Can't you just re-enter LR, fast travel to a point near Ulysses Temple, and pick up your stashed loot that way?

I did something similar, left hundreds of pounds of loot in a locker on top of one of the buildings near the end, and picked it up later.

And did the same thing with a hundred or so pounds stashed in the Crow's Nest.

Pretty much this. The only DLC location you can't go back to after you finish is the Sierra Madre in Dead Money. The way I deal with that one is to stash my goodies in a trash can located right beside the exit gate to the Mojave. When I'm ready to leave I just empty out the can and do a short overburdened shuffle back to the Abandoned BoS Bunker.