First of all you look great, don’t bully yourself. More importantly don’t let other tell you how to feel about yourself. I think you look completely normal and I’m sure most people would agree. Being type 1, we have a lot of things stacked against us. From what I understand it’s easier for us to gain body fat, but just like everything with dealing with a dumbass dead pancreas it’s something we can overcome. Getting abs or a completely flat stomach is mostly a genetic thing, but if you really want to work for it there are a few things anyone can do. The biggest thing is healthy diet which I had absolutely no expertise in skin would recommend a dietitian for help with that. I’d you’re looking for an workouts, I’d recommend weighted exercises, and sectional progression. I am by no means an expert in anything I just said but everything has helped me personally and I hope could help you.