No, you're not being selfish. He sounds quite abusive towards you. When it gets to the point that you feel too intimidated to question his behaviours or voice your opinion, this means the relationship is no longer equal. You are no longer equal partners, where there is 'give and take' and where each person feels safe and respected to respectfully voice their difference of opinion/make suggestions for compromise etc.
The fact your adult children are advising that you leave him, is really 'telling.' Marriage isn't meant to be a prison sentence! 35 years is about 25 years more than many countries imprison perpetrators of murder for!
Life is short. Really short. Why live in fear and be made to feel like you have to watch every word you say to him in case he yells? How lonely for you :(
No one should be 'punished' in marriage. It's meant to be about love, shared values, shared experiences and mutual respect. Not about cowering, crying, being shouted at and being too afraid to speak out in case your partner yells at you. That's not 'living,' that's merely 'existing...'
It takes a lot of courage and organising to prepare to leave someone after such a long marriage, so if you can, surround yourself with trusted friends and seek out legal advice before you announce you're leaving. Find out what your rights are. Think about where you can stay. What income you will have. Don't let these hurdles stop you though! Everything is surmountable with planning and proper legal advice.
Wishing you a new, abuse-free future and lots of future smiles and giggles 🌸🙏