I like the thought of being with someone, but whenever i am approached by anyone who is interested in me i feel physically gross?

So I'm only 17, we'll start there, and I've never been in any relationship mostly because i spent my high school life wallowing in social anxiety. glad those days are over.

I like fictional relationships, they get the butterflies going with all their cuteness and I always think to myself, 'I can't wait until I have something like that!'. Everything is fine when i'm not in any kind of relationship, whenever i think about it there is no initial doubt in my mind that one day i will be in love. However, this is changing recently. More people have started to approach me, asked for my number, told me I'm pretty, etc. Actually right now I am talking to someone who is wonderful to me, they're doing everything right and my mind is telling me that this is all too perfect but my body feels gross. not all of the time. just once or twice a day i'll feel the need to run away, block him on everything, tell him i don't want this, stop talking to him. Sometimes it just feels so incredibly awkward and wrong inside, not because of anything he is doing either.. he seems pretty keen but anytime it gets to something more than friendly flirting i start to.. get turned off him? I like the THOUGHT of being with him.. i picture it often and it makes me happy to think about but once its time to actually talk to him, sometimes that happy feeling stops and is replaced by repulsion.

This isn't the first time, just the most intense. For example, i had a crush on a guy all through high school but the second i was introduced to him after so long of liking him i lost feelings for him. its like he became human, and that grossed me out. Another time i was invited to a friends party, there was a guy there and i thought he was cute until i was later told he thought i was cute too. Instantly, grossed out, want nothing to do with him.

Now i know this may be a contributing factor too, but i've always been very alone and enjoyed it. I sat by myself everyday in high school, i live alone now and i really enjoy being alone, i never really feel lonely until i start to think about relationships and then i start to feel a little down.

Im just so confused, i have a great person right in front of me, who is into me and keen and wonderful and i can't help but feel repulsed. is this normal and is there anyway to know if it will stop?