In the past few days I've been experiencing alot of stress, as a direct result of that stress anger and rage have accompanied it. Today I threw a backpack and it shattered a set of shelves I was working on hanging. It really didn't make me feel better, I just had that"oh sh** what did I just do?" feeling. I'm afraid that this may expand into something worse, what can I do?

Is there any way you can confront the source of your stress? Relationship problems?? Work or school problems?? Crashing a backpack into the wall is more common than you think. But I can't give you advice unless I know what led up to this?????

The "oh ____!" moment is too late to do something about your anger. Think of three other things (that aren't destructive or hurtful) you could do before you reach that point when you get angry. There is a split second between the "trigger" and your reaction where you can choose another reaction.
I think you're like most other people with anger problems. A counselor once asked me when I started to get angry----have you always done this?---the answer was yes. Then he asked me if I wanted to learn a different way. I was dumbstruck! I had a choice as to how I could react? Sure, I answered. That's when I learned the secret: I don't have to react angrily. I can feel anger, it's ok----it's natural----but when I choose to act aggressively by becoming controlled by anger, then I have lost all power over myself and anyone else. If I want to retain my power---and have influence and some control over others, I have to "manage my emotions". All of them---not just anger. They'd have sadness managment classes if everyone went around feeling sad all the time when it disrupts their lives and the lives of others.