A lot of people go through life unable to enjoy the present because they are focused on the past; they can' t get over things that happened to them or opportunities they missed out. It' s a sad state of being.

In your case, it seems to be the opposite. You seem to be unable to fully enjoy the present because you are focused on some imagined future.

You have a yf who loves you and is still young. Cherish this time!

I hope you don' t feel that you are losing your YF if he ends up seeking out girls. If you love each other then that's not the case at all. You're still going to be the one he comes to for advice and guidance. You're still going to be the first one to hear about how his date went. You'll still be the one in whose house he crashes when he doesn't want to go back home. You actually kind of get to live the life of a straight kid vicariously through him. A bl friend recently had the honor of having his now adult YF's firstborn named after him. What a testament that is to the lifelong bond between a BL and his YF! Just because he grows up, doesn't mean it's over.