UVHM first playthrough help

I’m stuck at the Gluttonous Thresher in Ultimate Vault Hunter mode in Borderlands 2. He keeps two hitting me with those stupid spikes. I’m looking for help in defeating him, and just basically helping me through UVHM.
I have a level 54 Assassin. I haven’t been playing Borderlands for too long, maybe a year or two. But I’ve litteraly never played with anyone before. I’ve always been on my own.
My Gamertag is ShadowOrcSlayer if anyone wants to help me out.