Maybe you don't know all the answers, but the important thing is that he WILL be back. Just keep that thought with you when you are struggling. And don't worry about feeling dependant ... you need a constant in your life that you know you can share your feelings with. You share so much personal thoughts and fears with him, its only natural that you feel "attached" because he may be the only person you feel comfortable sharing those thing with right now ... and thats okay. Dependance is something that naturally (for a lot of people) comes with therapy. It did with me, and I can assure you there are others out there who feel the same way.
Try not to focus on how OFTEN you get to see him, but just that you DO get to see him. Right now you're used to seeing him more frequently, but just give the semester a little more time, and 2 weeks isn't going to seem as bad.
hang in there, and try not to doubt yourself so much (I know Waaaaay easier said than done, but i have faith in you )

Jacq