Okay, thank you for more details. Wow, you guys really are close and sound very compatible as well. I don't think you are overthinking this....it's not unusual to fall in love with someone with whom you share so much, etc.
You didn't answer my question if he had been involved with any other women since being your friend? Is there any possibility that he is gay? And that is why he's not into you romantically? If it's not that, then he is either not attracted to you in that manner, or is really closed off for some reason sexually or afraid of being hurt romantically? Ugh. This is a dilemma. I do think that if it is going to become increasingly difficult for you to be this close to him, without the relatioship turning into a true couple on all levels.
You need to decide if you can maintain this friendship, without romantic love. If you can, then I would not bring it up further. If you feel you cannot, as it's too hurtful then I would let him know how this is bothering you and that you are lost as to what to do. Remember he is your best friend and you can tell him this. Ask him point blank if he only sees you as a friend, and if he has ever considered you as a girlfriend. To be honest, I think he will say no, otherwise I can't imagine that he wouldn't have moved into a more romantic relationship with you.
So, go ahead and just ask him and tell him you are having trouble with the closeness because you are in love with him. I don't think you need to hide this from him....as he is so close to you. Let me know how it goes....Please click ACCEPT, if satisfied. If not, then please reply with more questions. Thank you!