Think twice, then maybe one more time.
All I have to say is, there were two things that I didn't want to do in the Marine Corps: Be a mechanic, or work with computers. And guess what my job is? I'm a freaking system administrator. I work with computers ALL DAY LONG. I got put in a job that I didn't want to do for 5 years, and I couldn't be happier. Being a Marine is probably one of the best decisions anyone could ever make. I watched the other services throughout MOS school, and they just don't measure up to the high standards of the Marine Corps. And they know it. That's why when we walk on the sidewalk, everyone else moves for US. Haha. It's kind of funny actually. But seriously though, if you haven't quit the DEP yet, I'd really think about it first, because being a Marine is truly an honor and a privilege if you can get through boot. It will be one of the most maturing and life changing experiences of your life. Don't get me wrong, it's not always perfect, and there will be some bullcrap you will have to put up with. But it is what it is, and it will be a great experience when you look back.
If you really really really just must be a Doc though, I'd go the Navy Corpsman route.