I could have written this. I've found my anger is getting a lot worse as I get older as well. I also went from having very few responsibilities and taking care of myself to having to take care of my entire family, and also my mother who is not even 60 yet and has stopped working. Not only has she stopped working but she is completely useless too because she had a bad accident and became disabled. I became a personal support worker overnight and had to drop out of school to support everybody. I felt like I was moving towards that stage in my life anyway but it was still very sudden and premature. I can say from what you've written that you are probably living a high-stress life the same as me and are suffering a bit from having to switch roles of parent/child and supporting your mother financially.
I have tons of stress and responsibilities to the point where I filed a lawsuit of my own against the place where my mother had her injury because I couldn't take it anymore and I felt I was really suffering from everything that happened. My father also passed away out of the blue which caused me to almost go full blown crazy. I've been trying to do a lot of things to try to reduce my stress: exercise, taking alternate routes to work/ home (because where I drive there is insane construction too), writing etc. I try to stay away from coming home to a bottle of wine to fix the problem because I don't want that to be an option for me. I have the odd drink here and there when I'm having dinner. If I find I'm in a situation where I'm going to implode I actually do start taking a deep breath and counting to 10. Do you have any hobbies that can calm you down or anything that can help you de-stress even for 30 minutes a day? You don't want to become a grumpy-asshole guy who everyone is afraid of.