what are these feelings

So its probably going to be difficult to answer completely right because your answers will be based off what I say but all answers welcome!!!
Extra info.. I'm 17 and in last year of high school.

So basically there's this guy. And I've known him my whole life. We would talk and tease each other ie he would mess up my hair or knew little things to tease me and he would laugh at my funny failures especially in sport until we both had tears of laughter. Anyway he left at the start of last year to go to Australia because he is out of high school, has a scholarship and he's working on medicine etc. Even though he was gone all year (my yr 12) my feelings didn't change and if anything they grew.. when he came back last year there was so much to catch up on! but not enough time to talk about everything. And it felt normal again and I was so happy. He left at the very end of December last year and I just feel so strongly but I don't want to tell him yet I'm not sure how he would react. I've felt this way for 4 years now (but known him my whole life) and it started as a crush. With me doing the most obscure things to get his attention(as you do as a 13 yr old). Over the years however I began just feeling serenely happy whenever he was around or even just remembering a good time. I no longer saw him as being perfect as I did when i was younger, I mean he has flaws... but I still love those flaws. Unfortunately for me it feels like unrequited love and I have no idea if the feelings are reciprocated because he doesn't know.. basically what I was meaning to ask is.. is this a crush or something more.. to me it defiantly feels like more( on my side) and has for awhile but its good to get peoples opinions. Obviously there's alot I've missed out but basically he would. Tease me. joke around.. and be serious with me as well..(inserting some good times XD, after a concert thing at youth group once, I got dizzy, everyone was walking past while i leaned against a truck and waited it out, he saw me and asked if i was ok and I said yep just give me a minute but instead he's like come here, so i slowly walked over to him and he gave me a piggy back to the van haha. And also after music practise he would give me and my friend a ride home, but he would always drop her off first even though dropping me off first would actually make more sense, theres so many more but you know that would be a novel) he's also gone far enough to joke about my future husband... whoever that may be... but he doesn't know my feelings and the only time I see him is at Christmas.. I still get butterflies now and again if me and someone talk about him. I obviously also miss him alot somedays, a song will play that reminds me of him and i can't help the longing i feel, but then there are days where I am still happy, And hopefully this Christmas i'll see him again!.. and this may seem weird.(and a little deep idk) I know, but Sometimes at night I'll just look at the stars and remind myself.. he sees these too.. even though he's away and even though the stars have moved.. there's a chance he's looking too.

A crush left un-challenged can often appear to turn into something much more when in actuality, it is still just a crush.

You're 17 and there's so many good guys out there for you to discover, don't let yourself get hung up on someone who isn't available (due to distance). Be 17 and crush on guys you can actually have some fun with.

If he comes back from Oz to live and is all over you then you can pick this back up but don't keep your life on hold for someone who can't give you a proper relationship.

Hope that helps?

No it helps thank you! I mean its going to be hard either way so that's going to be a reality I'm going to have to face but what you said makes sense!.. So although it may be hard I will try. ..emphasis on try XD.