I’m lucky enough to have been born with the sort of brain that keeps my overall mood on an even keel, no matter how many annoying things I force myself to do.

From my understanding of emotional ranges I would say this statement places too much importance on a biological type. There are definitely people who are born with chemical imbalances that result in fluctuating, diminished, or exaggerated emotional ranges, but for the majority, it is more accurate to say that emotional response habitually and cognitively shaped. I would suggest that this statement is more accurate of your situation:

I like analyzing myself, and so most of my basic emotions are accompanied by thoughts about those emotions, and I suspect that this process of deliberate analysis causes the actual emotions to be less intense.

You have developed a belief system that has led to a pattern of habituation that dampens and redirects your emotional outputs.

Strong belief in rational/other ideology -> pursuing certain actions -> overtime actions become habitualized-> actions develop new cognitive and emotional responses that result in dampening and redirecting strong emotional output.

I would suggest that when you are faced with situations that contradict your ideological base it questions the entire system. You are a cognitively gifted person, so if you encounter one of these situations your mind goes into overdrive reanalyzing all previous evaluations. The result is all the "little annoying things that you have forced yourself to do" over the past months lose their rationale causing a huge flood of negative/doubtful emotions. I have experienced this myself, in my mind I think of it as the over thinkers equivalent of anger management issues.

People who have anger management do not know how to deal with little things that make them mad. Their anger is improperly managed and slowly builds up into a giant torrent of emotions, until the time comes when they explode.

My advice would be a better balance between growth and fortification. Growth comes from pushing yourself to reach new limits; however, if you do not give yourself a break every now and then it is dangerous. Fortification is dealing with the immediate protection of happiness and stability. The majority is excessive in their fortifications and lacks an impetus for growth. You are the minority in your incredibly strong impetus for growth. Just tone it down sometimes. If you like something sometimes you need to do it regardless of rationale. If you don’t like something, sometimes you need a break from it, regardless of rationale. If the majority of your day is spent justifying doing things you find to be annoying, you might want to rethink some of your routines.

Best of luck.