Why do I (26M) feel so ashamed about having sex?

Weird question but I always feel so ashamed about having sex. And it’s not like I grew up in a religious household or something. I did lose my virginity at 18, but ever since then I feel so ashamed about it. I didn’t do anything wrong, I know that I didn’t do anything wrong, but idk. I just feel really uncomfortable about it and it’s killing me. I know sex is a natural thing, I know I wasn’t expected to be a virgin my entire life, but I just can’t get rid of this feeling. I’m not religious, I’m not ashamed to buy condoms or anything like that, it’s just, I don’t know. Sex is a natural thing, but for me it’s just so weird. I don’t know. I just can’t stop thinking about it, I get headaches because of it, I just feel uncomfortable for no reason at all. I feel, empty inside, somehow. I don’t know. <br><br>I hate thinking about it, but I can’t get rid of the feeling. I don’t know, for me it’s just kinda like, ehh, idk.<br><br>Edit: I just want to say, thank you for all the replies. The people in this sub really helped me a lot, gave me a different perspective to see things from and I really appreciate that. I just want to say something here in more detail. I don’t know if anybody here has anxiety attacks, but the way I feel is really similar to having an anxiety attack. I just feel so, empty, and hollow and weird inside. That’s the best way I can describe it. I do think there is a lack of communication in my sexual relationships (me communicating with my partner), but I do believe there is some sort of mental or psychological component here too. This feeling isn’t just about sex, it’s about me personally. I have a hard time communicating with people in general, not just in sexual relationships. I did open up to my girlfriend about this and she understood. Thanks again to everybody who commented.