Sorry to hear about the personality change, that really stinks, but it is totally one of the pcs symptoms. Have you had a CT scan or seen a neurologist? The CT will make sure that there is nothing physically wrong that can be fixed and the neurologist may be able to help. (I have heard that they can work wonders) personally I know a little about what your saying, but my personality thing is that I am cranky because I have had a constant headache for a year and a half. I have not seen a neurologist, but I plan to within the next six months, before I switch to a new college in January. The PCS caused me to get the first C of my life, it has caused me to have to stop all my favorite activities like dancing, rock climbing, and doing anything that might raise my pulse. I have read in a few places that people learn "coping methods" but I have yet to find one. Meds are out because they actually make the problems worse and the only other thing I can think of is to stay by myself in a dark room sleeping all the time...ha ha ha...We still have to live life and we want to live it to the fullest....grrrrrrrrrrrr... OK, anyways,
The advise I would give is try to find ways to slowly, slowly push yourself out of your newly made shell. Realize that you might be a different person on the outside, but in reality that same person is still there. Maybe focus more on studies and reading on your own and when you feel better go out with friends. I will admit, I think I weighed down my friends and I think switching schools this year is going to be the best thing for them, and going to a school with thousands of students where I can just hide when I need to will be good for my health if not my desires...
I'm sorry I am so gloomy, lately my headaches have been really bad making me grumpy.
I will say a prayer for you!
Good luck on your journey!