its okay. dont feel bad about yourself. one bad decision whilst you were free and single. nobody got hurt and you learned a valuable lesson. buy a vibrator now and wait till you meet a guy who cares for you and who you care for before having sex again.
you are young, you made a mistake. your allowed one reckless mistake. we have all been there. id say most have a sexual experience they regret.
the important thing now is to forgive yourself. the way you are talking its as if you were forced. you need to syop feeling dirty, bad, ashamed and stop scrubbing yourself. your clean. you have only slept with 3 guys-its nothing to be ashamed of. and nobody will think your a slut
put it down to a lesson learned and move on. if you are still feeling rotten about this in a few weeks-see a counselor or a sex therapist
you cant let one bad experience like this turn you off men or sex. you need to ebrace your sexuality. its perfectly normal to enjoy sex-just save it for someone you trust and have feelings for in future
best of luck xx
"Don't ask a question if you can't handle the answer".