Anger Management issues?

For the most part I am a laid back person. I'm 25 years old, I'm competitive, I work in sales, involved in sports, very outgoing. I've been like this most of my life but I feel like my natural emotional response in any given extreme emotional situation is anger. I can laugh most things off, but sometimes there are certain things or certain people that anger me so much that it consumes me. I sometimes lash out at people when it is undesrved, and I feel like I don't act enough when it is warranted, I tend to bottle up my extremely angry feelings up instead. When I don't act, I've been driven to be so angry that I've either pictured or fantasized of killing someone on rare occasions. Now I know everyone gets that mad once in a while, but I've almost gotten to the point where I have no apathy for random people anymore at all. I assume people would rather screw me over than help me. One weird thing about me is I listen to extremely hardcore heavy death metal music; it wasn't a phase as a kid, I'm 25 and I still listen to it religiously. I don't know if that is even relevant.

I haven't had any traumatic experiences in my life or anything: parents divorced when I was 21 years old, was picked on quite a bit as a child because of my smaller size at the time, but that's about it.

Basically I'm sick of pushing people away with my angry personality and negative attitude. I almost feel like people are turned off of something about me before I even really get to know them, like they can see inside my soul before they even talk to me, and that they know that dark side of me. I want to be a happy person, but sometimes my anger almost depresses me. When people don't act the way I want them to I feel like they have something personally against me and that they're trying to get the best of or hurt me. Sometimes when I don't like someone, I do things to push their buttons to create a conflict, as if to give me a reason to get angry or lash out at them. I don't realize that I do these things until long after the fact.

This doesn't happen to me all the time, but often enough to make me wonder if I need help. Is it anger management issues or is it something deeper or more serious? Maybe I'm just worrying about nothing...
If I do have a problem, who do I go talk to? I dont know if I can afford a therapist or whatever people do. How do I find out if I need help what I should do to try and get help? No one is going to do this for me, I have to do it on my own...