Thank you for writing your thoughts and feelings with a clear explanation of the issue. I think the short-term approach is to find a counselor you can begin talking to about all these concerns and think that will be very important. Since you are 15 and are still in school you may want to talk to the guidance counselor about these issues and see if he or she can arrange for you to talk to someone on a regular basis about the concerns you have.
The issues you are having are very typical for your age. The embarrassment and restriction you feel from your parents’ religious beliefs seems to have heightened this struggle. The long-term goal is to invest in your own future and plan for being more independent and self-reliant. In other words, see your graduation from high school as a time where you can be more independent and on your own.
Finding someone to talk with now and planning for your future are essential.