I agree with this. If he isn't interested in you, then he shouldn't be engaging in overly affectionate behaviour. You're not going to be able to get over him if he is behaving this way. In the short-term it might seem sweet and make you feel good, but when you're older you'll look back on this behaviour and realise that is actually very unfair of him to do this to you. He's essentially dangling a treat in front of a dog and never handing it over. If you don't put a stop to this behaviour now there's a good chance you'll end up resenting him for leading you on like this later.
As for your main point, if you're still of school age then put this worry to the back of your mind. Chances are you won't even meet the person you're destined to be with until you're older. I started dating when I was 14, over the years I've had a few long-term partners and countless short-term flings, and I only met the girl I intend to someday propose to this year. I'm 29.
You've all the time in the world to find your Prince Charming and you're much too young to be worrying about never finding him! Focus on your studies, spend time on your hobbies and interests, and say yes to hanging out with friends and any opportunities that arise for meeting new people. You'll meet the one someday.