Fancied a girl for a year. Spoke to her. Now Hate her. HELP?

So I was at my cousins wedding in September 2017 and saw the most beautiful girl ever. I couldn't stop looking at her. It was legit love at first site.

I managed to find her Facebook through becoming friends with her cousin at the wedding. I stalked her Facebook everyday and stared at her pictures (ik sounds weird but this is how crazy I was over her). I didn't want to message her because I had my GCSE's that year and was too focussed on revising. After my GCSE's in my summer holidays (July 2018) I decided to message her. We spoke everyday for a few months and got very close. She is quite into me at the moment.

Btw her personality bangs. She's a very nice person.

But then suddenly I stopped liking her and now I don't want to talk to her. I try my best to avoid her texts and calls and I am on the verge of blocking her off everything. Theres NO REASON at all as to why I stopped liking her.

I try to convince myself to start liking her again but can't and want to stay well away from her.

What do you recommend I should do? and is this normal?