I keep messin' up.?

Everytime I make a commitment to stay away from sinful things and fully devote my life to God, I always mess up. I either do it without thinkin, by accident, on purpose even though I knoww it's wrong, but I always do. Every year there's a certain 'problem' that I go through. I'm tryin to stop messin up, but it's hard. I don't want to go to hell. any advice?