Anger issues aren't so much about feeling anger, even intense anger, but more about how you handle that anger. If the anger has control of you, and you turn into a raging lunatic or find yourself behaving in a way that's destructive, even if it's towards the person you're angry with (i'm not talking about venting or just raising your voice), then you have anger issues. If you find yourself hanging onto anger, nursing it, defending it, cultivating it, allowing it to blind you from more realistic perspectives of a situation or person, then you have anger issues.
If you've been wronged, especially in a relationship, feeling anger that comes and goes in waves, even for years, is natural. On the other hand, if you've got a bad case of self-righteous anger, it can be like an addiction as it's a very powerful feeling. If that's what you've got going on, please be aware that no matter what your ex did to you to bring about the anger, you're still giving her all the power by allowing yourself to live that way, be affected that way. That's not her problem. It's yours, and, yes, it's an anger issue you need to work on, mostly for your son's sake, but also for a better quality of life for yourself.