Is it normal not being able to come over guilt

It's okay to fuck.

Some parents can be controlling. The issue is that since you grow up around them you often don't even realise they are until you move out and gain your independence. While I'm sure you're right, they want what's best for you, some parents forget the fact that you're young, you need to experience what life has to offer. You'll make mistakes, you'll make great choices on your own. There's absolutely no need to feel guilty for experiencing something most people your age do. Sexual urges are natural and perfectly acceptable to be explored. It's important to remind yourself that you're in charge of your own life. Family has the right to offer advice, not make the choice harder or entirely for you. Perhaps you should speak to a therapist for advice if you still feel guilty. Negative feelings shouldn't be allowed to consume you. Especially not when it's regarding a positive and natural decision.

Sex is normal and natural.

I have to wonder what age your parents believe would be "old enough" for you to have sex. Maybe 50 years old?

Your parents have the right to believe whatever they choose - or, more likely, they have the right to hold on to whatever crap was poured into their heads when they were kids and to never develop the emotional maturity and intellectual curiosity to question the reality and usefulness of the rules they've lived by.

If you live with your parents, then conforming - or at least doing your best to appear to conform - to their rules is wise. Directly challenging people on a world-view that's founded on nothing more than belief, superstition and opinion rarely ends up in a positive place, particularly if the power-dynamic of the relationship means the challenger is in a weaker position.

You clearly believe that your parents have your best interests at heart, and that may well be true. But speaking as a parent, I'll let you in on a little secret: parents are people, and people are often wrong. The world is full of people who were left fucked up in all sorts of ways by their parents' best intentions. Since it sounds like your parents have done an excellent job of screwing up your attitudes towards sex, you may well be on the way to becoming another of those people.

The fact is that you did what you did with the guy, and you can't change that. Most people can think back on their lives and come up with a list of things they regret doing and not doing. That's the price we pay for living and being able to make decisions. If your parents are as protective as your post suggests, then I wouldn't be surprised if having sex with the guy was really the first significant decision you've ever made in your life, because your parents will have made all the important decisions - or manipulated into making the choices they wanted - up to that point. If that's so, then it wouldn't be surprising if you're basically not equipped to make sensible decisions because you've had no practice thinking things through rationally, considering the possible consequences of your choices and accepting full ownership of whatever you eventually decide to do.

Feeling guilty about something that you've done achieves nothing positive. The best we can do if we regret doing something is to try to learn from the experience and do our best not to make the same mistake in the future.

I think this issue is a lot more complicated than it may seem to some folks. I want to stress that your ideas, and opinions regarding this issue should be of significance here.

What are your beliefs about sexuality? What do you think, honey?

I may, or may not agree with your opinions, and that's okay, because you are the only one who has to live with your life choices. So do you know what you believe with regard to sexuality, religion, morals, values, etcetera?