Relationship advice

Hello everyone. I come here looking out for your advice. I have been with my boyfriend for 4.5 years. Amazing relationship. Awesome boyfriend. The problem is me. I know I love him. But I don't know if it's as a friend. We were best friends before becoming a couple. Thing is I dont get horny anymore. I dont feel the need to make out or even kiss him. I know he loves me because I told him I felt different and he begs me to work it out. What can I do? I do want to work it out. I know he does get excited and wants to touch me all the time. But he is very respectful. PLEASE I NEED HELP. What can I do to get those feelings back??? I'm 20 he's 22 and both virgins in first relationship. We are not having sex until married.