The problem is martial arts aren't about peace for me. They've become being better at violence than the other guy when you need to be.
Em, I can't argue with you on this point: whatever other people may experience, my own view of martial arts is that their essence is, at base, structured violence. And I personally have always found it difficult to see the peace-loving side of arts which teach you effective ways of delivering blows to soft tissue that may leave your assailant in mortal danger: a knifehand strike that can break a stack of three inch board without spacers, say, is going to do something to an attacker's larynx that I wouldn't want to have to visualize. The only peace I see associated with the MAs is the peace of mind that comes from knowing that you've done all you can to give yourself a possibly critical extra survival advantage should trouble find you, against your will and best efforts to avoid it. But the MAs are about destructive force, and its effective management, so far as I can see. So if you can't see the peaceful aspect of the MAs... you're not alone.
Where the damage is done is when this attitude bleeds into the rest of your life. How long are you upset after an altercation? I can tell myself it's water under the bridge but believing what I tell myself is a different story. I feel the peace aspect is like talking about the weather. The weather is whether you talk about it or not and is pretty obvious. I make no mistake that effective self-defense may result in the possibility of causing injury.
One thing that you might consider is that we are all very apt to invest physical conflict situations with a lot of other emotional linkages, because a good deal of our lives we feel ourselves vulnerable to the will of others. People who work in office situations with a brutalitarian boss, or with nasty colleagues; people who deal with an often extremely rude public in a service capacity; people with emotionally abusive and manipulative family situations.... the list of ways we can, and often do, get treated badly, unfairly, or at best in a completely arbitrary way, is basically endless. And I have the feeling that in a situation where you are physically threatened—the most immediate, dire threat of all—your sense of, and blazing anger at, all these other vulnerabilities kicks in, and you see red... and go on seeing it. When people, in a physical altercation, go berserk and inflict serious damage on the attacker or attackers, way beyond what anyone who knows them imagines them physically or emotionally capable of, I would love to bet high that it's that final-straw rage reaction, fueled by all the other places where they feel pushed around, that's feeding that kind of literally frightening explosive anger-driven violence.
I'm feeling a moral impass with myself, the details I don't think I should share until certain matters are resolved. The problem is that I'm torn between two rights/wrongs and I have to make a choice based on faith. Those are the most difficult choices for me. I've concluded that my outlook and attitude are responsible, as always, for the situation I'm in. There is nothing more dishonorable than not admitting to being responsible for your actions if/once you are aware. I hope I'm reading myself right. I've also been getting some council.
Counseling will very likely help, Em. Long-suppresed, virulent anger, if that's what's involved, definitely needs to be looked into; it can literally make you sick, if you don't.
And if you feel that the sanctioned violence inherent in the MAs tends to feed something like that in you, then yes, it might be wise to give it a pass for a while, till some of these other issues can be resolved... I for one certainly don't want to give you any kind of bland reassurance that no, the MAs can only do you good, they can be a kind of tranquil meditative exercise, etc. etc. Your instincts in this particular matter strike me as worth paying serious attention to.