I am a slut, but i want to change?

okay i already know that i am a slut, but just because im promiscuous doesnt mean im a bad person. I am a very good person to be around actually but when it comes to im very loose with myself. im YOUNG (not legal) ive had with about idk... 15 guys YES I KNOW ITS BAD! i dont know what the f*** is wrong with me or what was going through my head, i just wanted attention i guess or to fit in with the wrong crowds. i live in a small town, so word gets around fast, but now i have a boyfriend of almost 8 months and i love him to death. I need him in my life and i just cant stop thinkin about my past, he doesnt even know that ive been with soo many people, but i dont know what to do, how do i go about changing this reputation for myself and getting people to respect me?