I’m so emotionally tired 😔

So I’m 19. I’ve been with my boyfriend for 5 years but we started living together 8 months ago. When we first got together we would have sex all the time. He would make me feel sexy with his words. He would talk dirty to me. He made me feel wanted. But lately I’m feeling so unwanted. Idek how long it’s been since we’ve had sex. And he never wants to do anything. I try to do something and he always ends up pushing me off. Its been like this ever since i started gaining weight this last year. He’s even made comments about my weight. And honestly I’m just so emotionally drained. I try so hard with my weight but it’s so hard when I’m also depressed. I just don’t know what to do at this point. It hurts me so much that me gaining weight has affected the way he looks at me. Mind you I always catch him watching porn type stuff and looking at other girls on his phone and it just really hurts me and makes me feel like I’m the problem. I just don’t understand why he wants nothing to do with me but wants to watch all these skinnier prettier women. No matter how much I talk to him nothing changes.