Hey Julianna! 🙂 I’m not really an expert, but I totally get what you’re going through. It’s that whole thing like “well, intellectually I know it’s not an issue, but I’ve been raised in a society where sex is a huge deal and your participation in it can determine a lot about your status in social life!”
For internalized negative emotions like that, the only thing I’ve found that really works (for me personally, at least — it’s the only thing I have to work off!) is self-talk. First, focus on identifying your anxieties when they arise. Don’t worry about anything else; just get to the point where whenever they crop up, you can point at them and go “HA! There! That’s it!” Then come up with a simple refutation that feels honest to you and calms you down… maybe something like, “Even though it seems important, I know it really isn’t, and doesn’t have any effect on my value as a human being.” Make it your own! Whatever works best. Now, every time you identify the anxieties, throw that mantra at it. At first it may feel like you’re faking it, but that’s beside the point; just persevere! The more you say it to yourself, the more second-nature it will become to say it, until eventually (hopefully) any time those anxieties start to arise, you’ll subconsciously start calming down before you even have to try.
I’m not a professional at all… this is just what’s worked for me. If you see a therapist or doctor, you might talk to them; I’m sure they’ll have a lot of other good self-calming techniques!