I need motivation!

I went back to school this semester, and since school came with a free gym membership, I decided to make weight loss and overall health a goal (not to mention I don't have money for alcohol or junk anymore). I started out about ten pounds overweight. In about 8 weeks I lost 15-17 pounds, and I ran my first 5k in over 7 years. None of my pants fit me and I can wear shirts I haven't been able to wear before.

I've kept it off, but I haven't gone to the gym in almost a month, and I've realized finals are coming up so I'm eating and drinking way more than I should. I keep making up excuses like "I work hard so I deserve this treat" or "finals are coming so I need to use the time to study"

I know I need to get back into my habits. I still have about 15 lbs to go to be my goal weight, and I'm falling out of shape. I tried on new smaller jeans, and people have told me I look smaller. I enjoy having a chin. But none of this has stopped me from pigging out and using food as a crutch. I'm even more worried with holidays and finals coming. What do I need to motivate me? Any suggestions?