How to deal with constant anger and frustration?

I am inquiring about potential anger management.

I have noticed a pattern of behavior, largely related to my pain level and frustration due to a physical condition that has progressed since childhood. This condition robbed me of my ability to sit, stand, or walk for several years collectively. The longest period consistently was 1.5 years. During this time, the extreme pain and frustration of losing my independence caused me to become very angry at anything and nothing. It got so bad, I could not stand to even be around myself and would often use prescribed medication to sleep as much as possible to avoid heated arguments with my girlfriend. After 1.5 years, a solution (although not ideal and likely temporary) was provided and I began to show a lot of improvement. That said, my fiance and I continued to argue over petty things as most couples do. These small arguments would build into huge explosions on both parts where very hurtful things were said on both parts. At this time, we both apologized and agreed to do better. It lasted a few months then started again and would repeat for years. The major factor in many of these arguments stemmed from my words being twisted or things I never said being blamed on me. But nothing changed. I came over to her home before work to spend time together. What started as a calm and constructive inquiry, quickly turned into a huge argument. I felt as though my partner intentionally went out of her way to make me angry and escalated the argument to the point where I no longer wanted anything to do with her and began loading my things into my car. Before I left, I walked back in and apologized for my words of anger. I received no apology. Now I was being dragged into another senseless argument in which my disability was used to be hurtful and as a part of a mute point, I walked out to her screaming more words from the kitchen. I stopped listening so I did not hear nor wanted to hear what she said. I ended the relationship after 6 years. There was no alternative I could see and after hearing such a low and despicable Insult, I could not forgive it. I received several texts after where she tried to put all of the blame on me as usual and then proceeded to state that I did not hear what she said as I stood less than two feet away. I know exactly what I heard. This anger has started to also show at my work when people do insanely stupid things, then blame me for it. I have noticed that I have been responding much more harshly in tone and often shut down any information that is not relevant to my job function. So far, it has not affected any of my family or co-workers at all. Yet I am concerned that I may be lacking in a method to de-escalate my temper when humans have pushed my buttons to the point of blowing up on them. I would appreciate any realistic advice on this issue. Please do not reply with something cliche such as counting to 10. It does not work and will only increase my anger even more.

Thank you.