I feel unloved by my husband.. here’s why

So at the beginning of July I had my Husband’s Ex message me sending me screenshots of my Husband FB messaging her asking how she’s doing and she’s been on his mind, 2 days later we had some bank statements come in and I happened to open it and My Husband has been paying for an Onlyfans account (I don’t believe in buying porn or watching porn, and I’m not judging those who do it’s just my opinion) My husband and I have been struggling for money, and he gets upset when I ask for gas money or money for my prescriptions. He was paying $80 a month for Onlyfans, during this time my husband has turned down having sex with me, doesn’t touch me intimately anymore, and always says “I’m too tired” when I ask for sex. I feel like he doesn’t find me attractive anymore, I’ve gained a little weight over the past months and I just feel like maybe I just don’t turn him on anymore. Before He always used to jump my bones, and tell me how hot/ sexy I was. He used to always want to have sex with me. Am I doing something wrong? I’ll try to initiate sex and he just turns it down, if anything he’ll let me jerk him off but he doesn’t want to get me off. It’s to the point I’ve been legit crying myself I sleep at night, how can I fix this?