I have gained back 10 pounds already and am terrified that I will gain back all the weight. First of all, you haven't lost it all. The information and perspective you had been acquiring is still within you, it's just buried under stress and old behaviors. From a psychological viewpoint, this is extremely important as it keeps people from falling apart. Instead of beating yourself up, use the presence of old behaviors as a signal that the stress you are under is great, and that you need to get some extra support for yourself.
Counseling is another resource for more support.
Your school may have student counseling services but if not, call LCL to schedule an appointment. I am a senior attorney and have been thinking about contacting your office for awhile now. Now I don't want to call. Rule 8.3 Reporting Professional Conduct went into effect on March 1, 1998. In essence, the rule now requires lawyers to report serious violations of ethical duty by lawyers and judges.