OK, I wasn't sure if you were just needing to vent or wanting some advice. So yes, learning to calm down and channel your anger is the best thing you can do. Some of the steps you are taking are great so keep with them.
Unfortunately, because some people are jerks and drunk people are even worse, they can be real triggers for anger - I've had to deal with some antagonistic drunks in the past and I've found the only thing that works is to be very firm with them. Your advantage is that you're the one in charge of your faculties (unless your drunk too of course) so you can be in charge of the situation too, but you'll only be able to do that if your temper is under control. I'm not a fiery person but I've had a deep seated anger since in was young, I used to clamp down on my anger, kind of the opposite to you but after a few years of psychotherapy and learning to better express my feelings and stand up for myself, I was better able to channel my anger productively when needed.
If all else fails try changing carriages (trains), sitting near the driver (buses), travelling in a group or travelling at times that avoid the worst of the drunk passengers. Being trans* means getting into a fight in public means the consequences for you could be worse than they might otherwise be, it shouldn't be but that's the way it is.
