It is too late to think about your parents and cultural differences, you should have thought about this before you got into relationship. This is not something which has come up with spending time together; these issues are always there when Hindu-Muslim starts seeing each other. As far as orthodox nature of your in laws is concern, it is a cultural difference between two community and you have to accept it and live with it. I do not understand that what kind of love it is where he is not ready to give you freedom to wear and express yourself? You have to compromise on many issues. If you are ready, go ahead otherwise just rethink about your decision of getting married to him.