How can I not feel like I'm cheating on my former love?

Hi, i need your help. I promise I won’t ask anything immature, or something i already know the answer to. So here it goes. I dated a boy who was my best friend back when I was a freshman. I was in 9th, he was in 11th. He was very very funny, but he was very very large. And he had the cutest hair, but the biggest head. Then I dated another one that same here. Completely opposite. He wasn’t very funny, but knew how to kiss and hug. He wasn’t that cute, but he was skinny. He wasn’t fun to hang out with at all, but he was popular. The other guy was clearly a way better person to hang out with. I went into these relationships thinking that I would find love. But all i found were flaws. Which is very wrong. These two boys both wanted me very much, and both respected me. They both told me they loved me, but i kept backing out. Then I found the love of my life. I put everything I had in my life into that friendship and “togetherness” (since we weren’t technically dating.) And come to find out, he actually wanted me back. So I put forth my effort, he gave some effort, and then he left. I lost everything I had into that relationship. Which of that, my heart. Now anytime i get closer to a guy, I feel like im cheating on my former love! I don’t want to like anyone else because I feel like i still have to be faithful to my former love! So i ask, does anyone out there know what on earth I should do? It would be greatly appreciated. I will funmail you on any help you’ve given me. Thank you, God Bless.