Is it normal to feel like this?

This isn't really a is it normal question, but please I need help, advice or just someone to say I am the same. It will be long but I could use the help.

Im a shy girl, who worries a lot. My family are really close we always have been. Me my mum and dad and sister. I always loved doing things as a family with them in school I had lots of friends, high school was a bit different no one seemed to understand me because I was quiet I couldn't come out of my shell and I was bullied a lot which made me even worse. College I knew before I started would be hard because im not a party animal ive never liked it, at 16 I worried about growing up because I knew I'd be left behind. And I was. Now all I do is work I have one close friend from high school but she has her own friends and is always too busy for me. I sit at home most of the time.. and its started to get me down I feel like im missing out on so much, I feel like im letting my parents down. My sister is growing up now she has loads of friends and talks about going on the town even though shes only 15. I feel like the odd one out.

A couple of months ago, I was at the local pool and I met a guy there, he was quiet like me. And he was so easy to talk to I felt so comfortable around him. We didn't exchange numbers. But a few weeks later I added him on facebook! He was going every week, sometimes missing weeks because of work. I chatted to him and it was great. I thought I'd finally found someone like me. I kept chatting every few days not wanting to be pushy or annoying, he told me close things and flirted with me, told me when he couldn't make it to swimming and when he could. Then he started being 'off' with me, he blank me or be blunt so I just took a step back. I met him at swimming again and he seemed fine, so I started messaging again, he invited me round to his when his mum had moved out ( he was buying her house) and flirted more. Then at swimming he told me he was on a dating website and how h'd met a few girls from it. Then after all this he seemed completely off. I'd message him to ask him how he was and he'd just reply 'yeah' not trying to make convo like usual. I don't know what ive done wrong, but inside its getting me down, I really thought I'd found someone like me.

You'll all say there is plenty more fish in the sea. But he's the only one in 20 years that I have found who would be perfect for me. And he's being like this now. Im not pushing for a relationship. Just a friend to be around..
So what should I do? Try talking to him and if he is 'off' ask if im bothering him? take the hint? He has only ever messaged me first twice..
I don't know.