I love him..but i dont know if im just fooling myself and maybe my love towards him has faded
You're too young to know what love is. You might have an emotional connection to him, but that's not love. Love is totally trusting someone, because you have excellent communication, and share wonderful things together, whether it's sex or something else that helps to bond the two of you.
In real life the "Feeling" of being in love waxes and wanes. It comes and goes. If you want to rekindle the feeling, it takes work. What work have you done to rekindle the feeling?
If you leave someone anytime that feeling fades, you will always be alone, because it always fades without action. So, just because the feeling fades, doesn't mean you cannot be together. Work on doing new things together. Going to new places, new restaurants, having new daring adventures.
As far as the sex thing goes, he may be a very nervous person, or he may watch too much porn, so he needs more stimulation to get lead in his pencil. This should not happen to a 19 year old man, who is at the peak of his hormones and sexuality. So, if it's a porn issue, he should cut his porn watching in half at least.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)