To request having your account deleted, you can go here:
http://www.medhelp.org/health_pages/MedHelp/MedHelp---Account/show/618?cid=88
There's a link under the question for the contact information, where I suppose you just write in saying that you want to cancel your account. I'm not too sure if you have to state why you want to cancel it, just requesting it might suffice.
If you do delete, good luck with everything! By the way, I always thought it was funny that our usernames are similar, in the fact that we both have [astrological object] + [cute animal].