Hey dartmed,
Sorry to hear that the MCAT has you down. If it makes you feel better, many people undergo at least a little bit of sadness when they study/review for the MCAT; whether its disappointment from low scores, stupid mistakes, or the large time commitment, the MCAT has a way of making you feel bad. Just remember that you are not alone and that this is almost a rite of passage into medical school. Suffering in the short-term will be worth it in the long term. Regarding the lack of social life, that really does suck, but you need to make some time for a social life if you really want one. Considering that you still have a long ways to go before your exam, I would suggest taking one week off from MCAT and then one day (At least) off every week up until two weeks before the exam. Doing this will give you something to look forward to every week and refresh you too! Trust me, you want breaks. I tried studying without some days off and I burned out after a while. I ended up taking a longer break than if I had just taken a day off every week. The fact that you've got motivation to start studying already is very impressive. Don't give up!
Here's a quote that I find inspiring:
"Shoot for the moon, even if you miss, you'll be among the stars."
-AppleRind