Your worth, your value is not determined by what someone else makes.
Also, I’m a bit ignorant of this subject so forgive me if I get it wrong, but did he not go to school significantly longer for his MD than you did for yours?
I believe he also had to go through the hell that is residency, I didn’t believe nurses do.
If you’re envious of his salary, improve your skills, or your education. If you’re happy where you are at In life, then don’t let the fact that others make more than you interfere with that happiness.
No matter what you do, there will always be others who make more, one of those sad facts of life.