This is really really normal. In the US, the religious customs largely went away a long time ago, so we start having sex a lot younger than you are now, but that's how it is when we do start whenever that is. Look at sex like anything else in life -- the first time you try anything new that's important to you, you have doubts and insecurity about it. The more you do it, the more you learn about it, and the better you get at it. It stops being a big thing. This will happen with you as well. A piece of advice I can give you is, talk to your spouse when you're married about it. I know it will be difficult, more difficult in your culture than in mine, but it will lead to a better sex life. Ask what she likes, let her ask what you like, as you try things. Don't make it a huge mystery or it will stay a huge mystery. And if you didn't feel anxious about your marriage, that would be weird. You don't really know one another. But I'll tell you, even when you do, it still takes work and teamwork. As for the pain you had, that sometimes happens with masturbation and can also happen with sex with a partner -- sometimes you do it too hard, sometimes there isn't enough lubrication -- it's just part of learning. So again, just look at it like all the other things you learned to do in life. It's just like that. All the best to you.