Here's some advice from a man who has been in love, lost it, found it again.
There are not just two types of love. There are millions of types of love. Love is not a feeling. That is the misconception of children (and you are 19, you are still very much a child). Love is a bond. It is something built through time, energy, effort, and the consideration of both people. It is not nearly as cheap as a feeling.
My thoughts:
Why do you "know deep down in your heart [you will never end up with him]?" Do you really think 19 year old girls would ever know this kind of thing? Do you think that 30 year old women would know this? No one fucking knows. You actually have to be in a relationship with someone to figure this out.
"Disney" level love is fucking garbage. Trash. Filth. Real love is so much more beautiful and amazing than that manufactured bullshit. It's also uglier and way more raw. But it is real rather than a cheap theme park display. Love is not what you think it is and you might get a better look at it when you experience it.
You have one of the core conditions of love. You want a shared future. That is something essential to love.
You are not yet mature enough to be really capable of love.
My advice is, discard the love thing. You are not in it and I do not think you really know what it is. You can be like everyone else your age and ignore this advice and tell him you are in love and that is fine too, but sincerely, I hope you do not.
Instead, I think you should actually pursue a relationship with him and try it out. See if actual love develops. You are attractive of him, possessive of him, and he is so much on your mind that you are writing about him. Your feelings are real and sincere and you should pursue them. I think that is a beautiful thing. If it does not work out... you need to not live with him.
You cannot live with someone you are attracted to and hear them sleeping with other people. It is tremendously toxic. That is not what you want at all.
You absolutely should pursue him. Physically if he does not really get the message. Odds are, you are already talking to other guys, you are just not pursuing them. If he is not interested, move on and do not live with him.