It was last night, I caught a glimpse of something which I thought was a naked girl, I brushed it off bc I thought well it’s Reddit so you can’t help what you see on the homepage. Fast forward like 15 seconds  I notice he was getting.... harder. So I quickly say hm what are you looking at and I look and it’s that picture?? He tried to say he was looking at the comments but there were only 4 comment threads, a total of like 8 comments? This really upset me bc I’ve been feeling ugly/disgusting/unwanted by him recently and he’s been well aware of this. He proceeded to get angry at me for being upset, saying “are you fucking serious right now?” Saying he was NOT getting hard. Saying he just scrolled up back to the picture because he wanted to see what artist the album was made by, but there was a link to the artists YT in the last comment which he could’ve clicked.
He proceeded to belittle me and the situation, trying to make me feel stupid and irrational for being upset.
Also it should be noted he told me the other day that he sometimes wanks over other women in porn. And how he doesn’t want to fuck me much anymore bc we argue so much.
Am I overreacting in this situation? I feel like I’m being manipulated/taken advantage of/having everything blamed on me because of my sensitivity and mental health. I don’t have anyone to consult about the things we argue about / the things he does to upset me so I feel a bit lost. Maybe I am overreacting? Maybe all the arguments are my fault because they usually start because I get upset over something and he doesn’t like it. He says he’s “emotionally exhausted” and “cant be bothered to care for me when I get upset if it relates to him” 
I don’t really know how to feel. I’m constantly doubting my own feelings and being made to feel guilty for feeling bad feelings if he upsets me. Any advice?? Am i overreacting? 