Will I ever win again?

I have been treading water for months (since mid-March). I have not been winning or losing for a long long time. It's getting frustrating. Whenever I grind my way up, I start playing like a donkey and I lose it all. Last night, I won a $5+0.50 sit-n-go at Poker Stars, but then lost it all back at the open tables. I essentially did the same thing at UltimateBet. I am very frustrated right now.