Congratulations on your decision, I hope you're able to get this done and meet your goal by next June, it sounds like you've got a good plan so far. That's great that you're able to get this done at such a young age, you'll be feeling so much better about yourself as you go through the rest of your life.
I'm 24 and was only banded about two weeks ago. I wish I could have had this surgery 7 or 8 years ago (high school was hell

), but I'm glad I can at least do it now, rather than living like this into my 30's or 40's. I couldn't imagine another 10 years of being as overweight as I am now, it's just miserable. The sooner you can work on it, the better!
I can't offer any insight on the psych appointments, as I only had to have one, but I still wish you all the best and I hope everything goes really well for you. Keep us up-to-date on how things are going for you. Hitting your goal for graduation will give you a great emotional boost and I'm sure you'll feel awesome!