I am sick of the ups and downs too. Take advantage of every good moment while you can, and get through the bad ones with the faith that the down days won't drag on forever. Keep reminding yourself that you are worthwhile and that it is possible to be happy, even if you don't believe it, even if it sounds stupid or impossible right now. I know it's hard, but depression can be fought. Take it one day at a time.

Sending you lots of good vibes.