I don’t trust my SO

My SO let’s call him Max. Max and I have been together for 4 years. Our relationship has been rocky and I can admit that I’m dumb for staying. The first two years he would has sexual relations online (flirting, sending picture, etc) he got caught and apologized every time. I forgave him like an idiot. We were good for about a year, I thought he was becoming more trust worthy and thought okay this is going to work. Until I found out he recently is starting it again. He doesn’t know that I know. He doesn’t give me attention, he doesn’t tell me I’m beautiful. I feel like I’m just someone there in his life that he’s comfortable with but won’t leave. Max and I barley talk throughout the week. We live about 30 mins away from each other so I go there on the weekends. This is going to sound bad on my end - recently an ex has been giving me the attention Max hasn’t for years now. I’m not cheating, I haven’t done anything, but (let’s call him Noah) Noah tells me I’m beautiful and try’s to up lift me. He’s always been there. I know I’m not in love with max. But he’s my comfort. I know he’s talking to other females. He’s constantly mentally abusing me and I just can’t take it anymore. I just don’t know what to do. I have anxiety and depression and breaking up puts me in a full panic attack. I am so sad & I just need some guidance.