I hope your mum gets better. The same thing happens to me. One tiny good thing comes along for a while and now everything is falling apart. =/ I'll be posting a journal on it later.
Wow. I was finally at my wits ends earlier this week and found refuge on a forum. I don't know if it would help you but venting on there has really helped me this past week.
http://www.depressionhaven.org/phpBB2/index.php
The people there are very friendly and you may find someone who has gone through the same problems. I hope your Mom gets better though, and your grades too. I know the father problems, I hate mine >_>