You will likely have to change your look for work but outside of that be yourself always. I'm twice your age and still happiest with an androgynous, kind of goth/punk look. I do get weird looks now and then which play into my self esteem and paranoia issues but then at least I can tell myself that they are being judgmental about my style (superficial things) rather than about me as a person or how obvious I feel that my mental and emotional problems must be.

I've spent so much time trying to be what I was expected to be (by a judgmental family as well as general culture) and made myself miserable until I felt like I didn't know who I was or that I barely existed as an individual anymore. Now I'm back to trying to be myself regardless of what others think. Don't do what I did and don't compromise who you are and what you enjoy for what you think the world expects of you!

Self harm is another issue and that needs to be addressed separately. I've been there too and the impulse hasn't gone away, I'm just able to cope without it better now. Take care of yourself and be safe.