As a revert who was once in a nearly identical situation, I have to agree with other commenters telling you to be careful. If he’s older and relating to an 18 year old girl, that’s concerning. He shouldn’t even be speaking to you as a friend (especially for that long) if he was abiding by Islamic values. I learned over time that the steps muslim guys make (wanting to introduce you to family, talking deeply about marriage and the future, etc.) seem serious and genuine to reverts since that kind of talk is very serious according to western culture, but that’s just getting to know any girl for them because they don’t have any other halal outlet to speak to women. I’ve spoken to guys who were extremely attentive, who seemed protective and caring, who seemed very religious and even wore a turban, who told their family and friends about me, and I still ended up finding out that they were talking to a bunch of random women of my ethnicity (I was just the main girl they considered), their family had no idea of their behavior, they lied to me about aspects of Islam because I didn’t know where and how to find out yet, and more. Even someone I was deeply in love with came back a year+ later to confess everything to me. I also thought I was very mature for my age so I’d know if someone was betraying me. Now at 22, I think I’m still somewhat immature!