I think you have to acknowledge that losing weight this time isn't going to be like last time - and quit beating yourself up over it. It's not going to be fast and hard this time because losing weight is NOT the priority in your life - your school and job are. That's not a bad thing. It doesn't reflect poorly on you. It's not because you don't "want it bad enough"...it's because you are doing some other things that need to take priority right now!
That said, these changes are not a reason to eat like crud and sit around all day. I'm in a night school masters program and working too. It's hard. I had to accept that I was going to have to work differently to lose my "not-quite-a-freshman" 15. (Or 30. gulp.) I really started recognizing that if school and work are my priority, that eating right and working out regularly were going to eat into my recreation stuff. I also really started noticing that my eating and workout habits were affecting my ability to get stuff done - eating carbs makes me brain fuzzed and not working out actually makes it harder for me to get to sleep on time (and that makes it harder to get up on time to get to work early). Once I started thinking about how my diet and exercise affected my school and work, I got a little more motivation. (Ex. I might not burn enough calories to lose a ton of weight at the drop of a hat, but going to the gym would clear my mind enough to write a better report for my boss or my professor.)
The weight is coming off WAAAAAAAY slower than I'd like. And I know that if I didn't have school, I could get this done much more efficiently. But I know that I can do things at least a little healthier than I did during the first year of my program and I know that those little things have already added up to losing 8lbs in the last couple of months. The weight loss may not be setting any records, but I know that I'll be easily able to keep that weight off too.