I was diagnosed with ADHD a few years ago when I was 30.
I tried a few medications. When I as on Vyvanse, I noticed similar personality changes as what you described. Most notably, my sense of humour suffered. (And before on dexamphetamine, I was really grumpy when it wore off. So I did get into fights.)
Things got better after I changed to methylphenidate. For me, it's milder in the side effects.
Modafinil and nicotine patches also work reasonably well with only mild side effects. (See https://www.gwern.net/Nicotine about nicotine. Please don't start smoking.)
Caffeine never worked at all for me. Just messed with my sleep. L-Tryptophan seems to help me very slightly, but I have friends who report great effects, especially with sleep and mood.
Enough ranting, my point is: you can try different stimulants to see if there's anything else that works better for you.
Finding the minimal dose that still works is of course still a good idea.
I tried a few medications. When I as on Vyvanse, I noticed similar personality changes as what you described. Most notably, my sense of humour suffered. (And before on dexamphetamine, I was really grumpy when it wore off. So I did get into fights.)
Things got better after I changed to methylphenidate. For me, it's milder in the side effects.
Modafinil and nicotine patches also work reasonably well with only mild side effects. (See https://www.gwern.net/Nicotine about nicotine. Please don't start smoking.)
Caffeine never worked at all for me. Just messed with my sleep. L-Tryptophan seems to help me very slightly, but I have friends who report great effects, especially with sleep and mood.
Enough ranting, my point is: you can try different stimulants to see if there's anything else that works better for you.
Finding the minimal dose that still works is of course still a good idea.