How do you play against stalled games

I've been on a losing streak from my past few games and dropped all the way from 290 or so to 170 or so. I find that most of my games end up at the point where I keep defending or no captures happen until I eventually blunder, my defense falls, and I lose the game. Do you have any advice on how to attack after both you and the person your facing basically have every piece defended?
User is "xxserment" if you want to check my account.