Ok, I got 2 big glitches, one of which is annoying me a bit, the other is just straight up ruining my game. First one you've probably heared; as soon as I modded my weathered 10mm pistol, I get a grey screen that turns out to be a massive red box with an exclaimation point in the middle attached to my chest, and my gun goes invisible.
Next one makes me major rage. I was doing the "Birds of a Feather" side mission and it was going fine until after we killed the crazy dude. Simon won't move the body and the fourth NPC won't come, and when I go to try and deliver the package, Simon shoots me and it tells me I failed the mission. Also, my autosave is right where simon is just staring at the body, and my last manual save was 3 hours back at the Boulder City Showdown. I don't want to have to lose 3 freaking hours. Please help me.
Thanks, guys.

wait for the patch which is likely out tomorrow sometime.

Trust me, 3 hours is nothing compared to what some people have lost.

Nearly 50 hours i lost to it so you havent got a lot to worry about. bet some lost even more.