I think that the fact that you recognize that you have a problem is impressive. Most of the time, when people are abusive, or just plain jackasses, they don't know it. Or if they do, they won't admit it.
Do you exercise? Take up Yoga. Work out every night. Get your aggression out that way. Not that it can take the place of therapy, but a hard work out can help alleviate stress and anxiety.
How's your diet? A lot of junk, sugar and caffeine? you might want to take a look at that also. Maybe it's not just your mental outlook. Maybe you have unhealthy habits that contribute to your..well, less than sunny disposition.

Good luck. I wish you well.