I have been finding in my playthrough i will get an enemy down to 0 health and they just refuse to die, It keeps happenining in every single battle I am in and its getting frustrating to the point I want to start over. Anybody else had this problem??

I ran into the same issue two times before and was lucky I had an autosave nearby to roll back to. Sometimes loading a save doesn't help as well, it can happen again. I usually enter combat in ambush. I invest in stealth, move in closer and focus fire to take down 1 or 2 as fast as possible. I think sometimes if you kill something, especially smaller mobs, too fast they remain stuck and become untargetable then you get stuck in combat and get hit by them constantly. I noticed this on smaller mobs that spawn in waves. Maybe it's related to the mobs getting attacked during their spawn animation, you kill them too fast so they are stuck in animation. This is of course my ignorant theory.

Anyways, till it's patched, quicksave is your friend.