What am I to do when so overwhelmed and can't seem to control my emotions?

I know exactly how you feel. Everytime things start to look up for me, somethign happens to knock me back down. It is so frustrating dealing with it all. I get that way at times. I scream and yell and throw things. It hurts the people I love. Then I feel extreme guilt for hurting everyone. I feel guilty for letting it swallow me up. The worst thing is when people tell me, oh it'll get better, but when? When does it get better? I keep hoping and praying, but I have doubts. I don't doubt God himself. I know he is there. I have felt him before but I doubt things ever getting better. I just keep praying. That's all I can tell you is keep praying.