Weight

So I recently ( 4 months) noticed I started to gain weight. My stomach is getting bigger and it really upsets me. I always fine myself eating when bored even though the voice in my head tells me I don’t need to eat I am full. I’m starting to hate how I look. I have always been a fit girl and never weighed more than 125 pounds. Now I’m an easy 135-140. It is so noticeable and I went up a pant size. My boyfriend hasn’t said anything and still calls me beautiful but it has effect my sex like to a point I don’t want to do it anymore because I hate my stomach. What do y’all do to help? I want to lose weight but being a full time college student in my internship semester it is nearly impossible to go to the gym unless it’s 12 am. Should I chew gum? Or what? I’m just so upset with myself for letting it get this far.