Bloat or...? HELP

Hey all! So recently I’ve noticed that when I eat unhealthy foods, my stomach bloats. I’m getting concerned that it’s started to turn into stomach fat. How do I learn to keep in shape and eat better foods? I’ve always been a skinny lady so this is starting to concern me 😭 It’s only my stomach! Pretty sure I’m not pregnant because I always use a condom and I took a test, said it was negative. Don’t mind the bruise, my friends dog jumped on me and her nails need to get cut badly lol.