Freelance is very tricky, especially in creative fields. It takes a lot of assertivity to ask fair prices and not let your clients stomp over you. I think every freelancer has to learn these lessons hard way when they're beginning. Sadly, many people still treat freelancing creators like some bored kids that stay at home and have nothing better to do and will gladly take anything ridiculous, underpaid project they come up with. And I also find it very mentally draining, as in you have to plan your day very carefully, one day of procrastinating and you can end up in a very bad place mentally. Still, I find remote freelancing better than any full time contract jobs. As long as I can I refuse to waste my life on commuting and pretending I'm doing something for 8 hours everyday while being unable to eat a full meal for dinner and having to get up at ungodly hours because the world will end if a graphic designer won't start their job before 9 am.

Sorry, I went on a personal rant here. Anyway, I'm sorry for your experiences and I hope you will continue to write and make art. I also made the decision I want to be an artist and dropped engineering master studies. Life is too short to not devote it to your passion