The anger problem is something that needs to be addressed, of course; but maybe keep a couple of things in mind:
You either could have controlled the anger and didn't think you had to; or else you're someone who is incapable of controlling anger.
I once read that genuine love always includes respect and admiration of the person we love. If you could have controlled the anger and didn't (because you didn't think you needed to, or didn't have to worry about controlling it); that would seem to indicate that you didn't respect your wife as someone worthy of being treated better. If you didn't respect her, chances are you really didn't love her either. You're both better off having ended the marriage. Consider it a case of "live and learn", and move on.
If you're someone who is simply incapable of controlling your anger, then you're someone who shouldn't be in a relationship at all (at least not until you can control anger). Someone with "issues" needs to focus on those if he hopes to iron them out. Being in a relationship isn't always the greatest thing for someone who needs to focus on his own issues. Your ex-wife was obviously not in the kind of relationship people deserve either; so separating was a positive step for both of you.
You're not alone in having lost a spouse over anger; and if you're like a lot of people in that situation, there's a good chance your wife actually cared about you but found the situation so unacceptable she felt she had no options but to leave. Be happy for whatever caring there has been between the two of you, and be happy that an unhealthy situation ended.
Besides trying to address the issue of managing your anger, it's probably a good idea to figure out what caused it. Sometimes people have anger because they don't understand "where someone else is coming from". They misinterpret motivations; or they may feel helpless in their own situation and get angry that the other person doesn't seem to be doing something to improve that situation. In other words, sometimes anger is "legitimate". Sometimes it's misguided or misplaced. I think it's important for you to first figure out if your anger was "legitimate", because if you're prone to misguided/misplaced anger it's going keep coming up over and over again in your life.