You most likely can handle it, so long as you are comfortable with it.
Most schools have outstanding medical facilities, support and therapists within their confines for students. Really - it is probably the easiest medical care of a high standard you may get in your life. The question is more how you feel about things and your ability to cope - given that you got in, everyone else thinks that you are capable as you are. So who knows what you can do with this improvement to your capability.
Feel free to PM me. I was diagnosed with similar over ten years ago, and episodes come and go (including during my MBA). There are plenty others it happens to also. The way I approach it is I would be pissed if it got in my way of doing the best thing for me - self confidence and nerves aside, I have been relatively capable.
As an aside, my diagnosis changed hugely when I came to business school from what anyone had given previously, as did the results. I wouldn't be so concerned about it, but - then again - the scale and symptoms of such things vary drastically.
Get the best GMAT Prep Resources with GMAT Club Premium Membership