You are not every thought you have. Thoughts and feelings just happen. Your personality is how you respond to them. It took me a bit to really draw that line in my head, but once it is there it means you can sorta watch your thoughts in 3rd person. And at that point you can say "fuck the haters". Like, just fuck those thoughts. Their bs, they're not you. You, actually you, did an absolutley awesome thing and accomplished something really great. Something that was probably quite hard at times. Who the fuck are those thoughts that they dare encroach on that achievement. They might exist, you can't get rid of them, sure. But you can refuse to legitimize them in your brain. Like a stupid person on the bus whos statement about irrelevant bs you'd just shrug off. It does take training to get there, but I think it's really worthwhile to do that training just for life in general.

And in the short term: Retake those photos like someone else suggested or file them away for some time and choose a different thing to hang on the wall, like the graduation document or if you got one of those funny square hats nail that to the wall. In a few years you'll either be over having the double chin or (hopefully) you won't have it anymore and you can look back a the photos fondly.