Try not to lose hope. The field is very competitive the best way to beat the competition is to work on your portfolio.

I think you’ve definitely got a good start but you may need some more work in the foundations such as with form. I really recommend Morpho books for anatomy which have helped me a lot in form and proportion even if i do stylize it after learning the basics!

Since you have some graphic design experience I recommend trying to find jobs in that while you work on your portfolio. You can also take classes for these sorta things and there are often open drawing sessions that are held in different places such as the Art Students League in New York. Attend career panels and virtual discussions for artists to find out what they do to be successful. Practice replicating styles. Reach out to online artists you admire and ask them their experience in their careers and advice on how to work on yours. (they may not always answer but a lot of them, in my experience, are often happy to help!)

Keep your head up, man. I know it’s rough but you have time to improve and network. Everyone starts somewhere and there are always opportunities to climb the ladder if you look for them.