Feeling insecure

So in the past 6 months or so I've gained a bit of weight on my tummy and I'm feeling really bad about it and I don't really know how to lose the weight. I know I don't eat the best but it's hard to eat well when I work 10 hour shifts and don't have food of my own to bring (I live with my bf and his parents). I feel like my boyfriend doesn't think I'm as attractive anymore because when I ask him about it he asks me to go to the gym with him.. I just I don't know can I get some feedback about how to maybe accept myself more or try to make me feel a little better? I don't really have anyone to talk to about this stuff