mood flips are exhausting....

I never realized just how bad my mood flips were...I guess I wasn't really paying attention..I think my girlfriend noticed though.. Even now, I was laughing and joking on the phone with her...and out of no where I just feel depressed & I'm fighting back tears... It's exhausting trying to keep up & trying to keep from letting it take over.. I can see that my depression got so bad because I let my mood get flipped into a negative state & I fed into it... I'm trying to keep from doing that now.. It's exhausting to go from being happy & on top of the world to feeling like you wanna die & all you want to do is drink... I'm fighting it tho! Keeping strong now that I know it's because of a mental disorder, I can fight this! :)