I'm not worthy

Idk if my husband loves me anymore. Ever since we were bf and gf I would sometimes feel like I was walking on eggshells watching everything I said or did. I thought my world would end without him I was and still am so in love with him. That before he used to blind about what he was doing I thought maybe this is normal.. I got pregnant at 15 and had him at 16. My mom wanted us to be married before the baby was born. I feel like I'm the one who pressured him into marrying me. He never asked if I actually wanted to marry him. He would say he wanted a civil union first then that we would get married the right way. And my mom would just tell me that it meant he didn't want to get married. So I listened to her and told him that no we have to get married. So we got married. Forward to a couple months later I was on his email ( yes I did go through his phone idk why but I've always felt like I wasn't worthy and I would always think he would be talking to girls like he would before) and I found pics of my sisters phone of her showing her cleavage and one in a really tight dress that almost showed her butt. ( I gained so much weight when I got pregnant I wasn't me and still am not.) my heart shattered. As much as it hurt I needed to know why he sent them to himself. ( I know my sister didn't do it for a fact) he told me he thought she had nice boobs and nice body. ( mind you I'm fat ass hell from just having a baby.) I would catch him searching up his exs on fb. He had a secret fb thy I found by looking through his phone. But of course I forgave him for everything.. why? Because I love him and I don't know what the hell i would do since I wasn't done with high school yet. I didn't have a job I didn't have anywhere to go. And I couldn't go my moms house because that's just a whole different story. Now that I've had a second baby I've gained more weight. I see how he looks at me. How everybody looks at me like I'm disgusting ( or could it just be all in my head) even my own mom calls me fat. My husband calls my fat and big boy straight up but behind jokes. I've tried losing weight but I don't know why I can't. I can't go to a gym because I don't work to be able to pay for one and he won't pay it for me. I just want to look good for him so I can be worthy of him to look at me. Since he doesn't pay attention to me like he does to every girls that passes by him.