Hey 1year later.
I am glad you made some improvements, that is something to value, as it proves your ability to change towards the direction you wished for.
I have some anger issues as well, though the anger bursts usually come up to me after it actually happened because I am very disciplined not to hurt others even in a verbal sense. Some people just are too much and we won't ever be able to change their ways or thinkings.
These people are people that use me or have abandoned me, or people who believe they are better humans than I am...
If it is an insult you are dealing with, e.g. "You are an asshole who couldn't do anything right." you should probably direct a strong thought like, "I am a good person who has achieved alot."
By destroying his insult, turning it into a compliment to yourself, you reinsure yourself in you. You will trust yourself more if you do this on a regular basis. Heck you should compliment yourself in all times you feel down, not just when outer attacks occur. Another method is forgiving the faults of the other person. By realizing that they are wrong and childish and therefore not completely in control themselves you keep them alive and human and you will take some steam out of your boat.
It also seems to me that as you have probably lived the way you don't want anymore, for quite some time, your body is programmed to react in patterns known to it. So obviously it will be hard to get out of these patterns, unless you recognize them. By reinsuring the good relationship of your mind to your body with the above mentioned technique the difference between your "mind" desires and "body" desires will eventually become more alike and you will react less violently. (THough I think you are not actually violent but your body reacts as if it will get into a violent situation).
I don't know how good you are at visualization, but in quiet happy times take the time and sit down and think of these pattern situations that piss you off... Instead on focusing on the wrongs you did or your madness, you respin old situations were you "failed" in your opinion, and just rewrite that scene to have a better peaceful conclusion. As your subconscious does not differentiate between unreal and real things it will program itself into your system and you might have an easier time to control yourself in the way you want the next time a situation like that comes up.
Now, most likely you have some barriers inside of yourself that keep you from your emotional sides. This has something to do with your past, unresolved issues. If you have a rock in a wound the wound will close but the rock will still be there, and layers of skin will grow over it. The rock will hurt you from time to time, even though it seems that it is gone. These metaphysical rocks have to be removed over the years, or you will feel pain at all times and it might get worse. I personally think you probably have removed such rocks over the course of your life, but there are still some remaining as it seems.
Getting in touch with your emotional side is key...
Hey cheer up though you have made alot of progress, and your journey will continue. Most likely you will become better at these things, as you truley desire them.
((IMHO putting all negative emotions down will result in the dam situation you have mentioned. If you put to much pressure on anything it will eventually break. The energies of anger and other emotions must have a way to live, as they are part of you, if you ignore them they will burst on you in bad places))
May blessings of insight and awareness overcome you, brother.