Why is it so hard to choose being strong and rightous over being weak and drowning ourselves in negative emotions?

Thats my question.
People look at me like a happy person, and I am. But thats only because I fight like hell to be a happy person sometimes. If I didn't try my best to be happy, I wouldn't be. I didn't always, and when things are hard I feel easily weak. I want to go back to old [terrible] crutches I used to rely on. I see myself as a insignifigant, guilty child instead of powerful, strong, and full of life and things to give.

So what do you do?

Thats my other question. What do you do to turn the weakness into strength? The sadness into optimism? Fear into hope? We cannot deny ourselves these emotions. Nobody never deals with negativity. Do you tell yourself something? Make art, music, ext? Something else? Or just feed the negativity because its easier?
Well, I'm trying to not feed my negativity, because it will surely turn into a full blown waste of living. So I guess it is a struggle we all have to fight, but how do you win?