Join the club. You wont get it back, whats done is done. If you have really done something wrong do teshuva on it but your innocents? you cant get that back.
Another thing, I’m a little confused between the first half of your paragraph and the second. In the first part you say,
“i feel like I lost a lot of my purity that I had when I left high school. is there any way for me to get that back?”
To me that sounds like you regret what you’ve done and you miss your innocents. Then you go on to say,
“I don’t want to get married and feel like the “smooth” (translate to another word that wont go through here) one”
That sounds like you dont regret what youve done and are happy youve “dirtied” yourself up because you dont want to be innocent. Conflicted?