I can literally imagine how hectic your schedule is but you still look pretty though!A part of what was said above is spot on but for me, your best bet on this one is getting enough sleep, changing your diet, and getting regular exercise.
So storytime, I'm 25 now and have been having the same issue. I work in marketing specifically content marketing which entails a ton of different tasks which are connected to each other. To give you an overview here is a list of what I am to implement every day for content. Which means I'm on my laptop pretty much most of my shift. I gained about the weight I lost when I was 22 in just a span of 3 months. When I noticed it I immediately went to a doctor he said going for serums and other treatments can help but changing your lifestyle would give you quicker results. Our body is connected in every way and changing just wee bit of habit will help.
I inserted a photo below just to give you a look at my progress.