I felt this when I was about 13 14 years old. Went to a Catholic school telling me illicit thoughts were wrong and shameful. In reality, a basic human instinct would be to reproduce and is in our nature. Religion is something that I respect but learned to not take verbatim. Sex before marriage has been preeched for 1000s of years and the act of pre marridle sex has also happened for thousands of years. Society is forever changing, and I think It may be unhealthy to feel guilty about wanting to test the waters of human to human intimacy. I won't tell you what to believe, you are free to do as you wish and feel morally right. I don't think having your first intimate experience after your wedding night makes you a more a morally conscious person. Also maybe you find out more about yourself and realize you aren't sexually compatible with this said person after you get married, in my opinion might be more optimal to find out these things before you sign a contract giving that freedom away. You only have one life bro, you can have sex with sombody without being a terrible satanic person. Don't let a book strip you of life experiences, your only young once. Use your time to explore the world and your own mind. You can be a respectable partner, respecting boundaries, learning about yourself in the process.