Others suggested this but go online to one of the more hook-up oriented dating sites (Agnostic.com definitely ain't that) and find one where you can explain yourself a little more. Someplace where you can say what you want. I wouldn't hide the fact that you're a virgin either. Many women would be intrigued by being a guys first. All this is assuming you want to go the hook-up route. I didn't 'technically' lose my virginity until I was 22 so even though your hormones are screaming at you there is no rush. Take precautions and never forget that even though you may just be hooking-up that is another human being you're with. I hope you find the right choice for you.

You might try OKCupid. You can answer questions about religion and get matches that factor that in, and leave the religion category on yourself blank, so you don’t risk easily being outed if someone you know sees your profile.

you're only 20? it's not really a bad thing. just don't go out and get an std first go'in

You have a lot of challenges to cope with and my heart goes out to you. This is a safe place to start - you can talk about your religious background and your journey toward questioning. You can also meet women safely because this is a social/conversation site more than a dating site.