How old are you? If you're a preteen or teen, I think being self-conscious is both normal and expected. Good for you for continuing to read in an environment where it's not encouraged!
Hiding your books also sounds pretty normal under the circumstances, although if you want to stop, you can work on that. I'm sure you don't want to go out and sign up for therapy (and your parents may not want to pay for it), but
this site has some cognitive behavioral therapy tools that you might like. CBT is a good modality for changing your own behaviors that you're not happy with.
Good luck, and thanks for reaching out!
