The thought of disapproval or rejection causes me to experience anxiety, but I also don't like myself. What do I do?

My apologies for not answering your question, because I couldn't even if I wanted to - what you do is completely up you, my dear! What I do want to point out is that this "but" you used in the middle of your sentence might rather be exchanged with "and"; as for in my experience - not accepting oneself seems to often be the real issue, while fearing rejection or disapproval may or may not only highlight what beliefs one has about him/herself. Please consider to see what beliefs about yourself you have and where did you obtain them from, if you feel like it :)

If you do not like yourself how will others like you? Start by accepting who you are and then the people around you will too.