He says he loves me yet he wants to be single. Any advice on what I should do?

When I look into his eyes I see that he truly loves me and I feel so incredibly lucky to have someone like him. Our relationship had been rocky in the past but now it was so much different; for the first time I felt like he really did care for and love me, but it was not until last week that I began to question it. Last week he broke up with me on the pretenses of him wanting to be single. I say pretenses only because I’m a girl who is scared and hurt and doesn’t want to believe all that he has told me. He says that he wants to work on himself; to become a better person and grow. I understand that completely and have no choice but to let him go. Words cannot describe how much I love him and that’s one of the reasons why I am posting this. I don’t know what to think or how to feel. I would like to possibly date but am too scared of rejection to even bring it up with him. In my irrational girl mind I see it as him wanting to be with other girls. Though it is completely understandable the idea of him searching for other girls just bothers the hell out of me due to him saying he loves me. I guess it is just something I will never understand. I want to stay really close with him (he is my best friend) yet I’m terrified of the day he gets another girl. Can anyone give some advice on what I should do?