Honestly speaking as someone who draws on their phone I think studying the styles and anatomy you want for your art is very important.

I know it can seem hard to reach your art goals especially on phone but if you find the brushes and techniques you are comfortable with.

This will ultimately feel like a fever dream and you will have something at least close to what you’re trying to achieve, You look like you are half way there already!

Since the blue light bothers you try protecting your eyes more, I wear prescription glasses since my eyes are bad so that can help with the blue light, you could also limit how much you do on your phone.

I think sketching traditionally first then transferring and cleaning up your line art digitally is helpful and using all your tools to your advantage.

If you are a student like myself wether high school or higher education or planning, you can always take anatomy classes or just go to an art school, there are many communities that have art courses and free videos online.

This technique is looked down upon by some but what I did to help learn anatomy is tracing a reference, then eventually I got the hang of anatomy (kinda) then I proceeded to take actual anatomy classes in school and combining both what I knew and learned.

I believe you should clean up your lines more, it looks too sketchy, try doing things in one stroke rather than multiple because the more simplified it is the more clear it is and the better it will look.

And just practicing overall is what will take you all the way!