Am I crazy or am I falling in love?

Okay so I met this guy in 8th grade. He had a younger brother that I just knew through him. Over a couple of summers we became great friends and the younger brother asked for my number. We became best friends and he was the one person I could talk to about ANYTHING. He and I started dating last fall and it lasted about 2 months. Since then things have changed and he has too. We are different people and old feelings are coming back. I am talking to him again and we will give it a second try. I want to know, because I feel like I love him with all my heart, if I am actually in love. He makes me feel like the only person in the world when I am with him. When I am happy I want to be with him to share my happiness, when I am sad I want to be with him because he supports me and he can always put a smile on my face. When I get mad at him I instantly think about how to fix things and how much I care about making things right with him. I want him to be there for me just as I want to be there for him in everything. He makes the sun shine and the moon rise at night. He makes me feel so special and I think I love him.