I like this guy but found out he is related to me today

I am on Holiday for a Wedding currently and so of course many different people are invited to the wedding. All of my family are native and so their English isn’t the best (I’m speaking relatively as I was born in England). Anyway, my mom told me that at the wedding there will be this family who will be there from Australia and there’s going to be a guy my age (he was actually 3 years older than me) at the wedding, which would last 1 week.
So of course I met this guy for the first time ever and he was really sweet and funny and we hung out together a lot. Both of our families were okay with it as they knew each other. We had a lot in common and whenever he spoke he always smiled and I really did begin to like him a lot. Literally I began to like him a lot to the point where I began to feel safe around him whenever I was walking around and the men were being creeps and kept staring.
We both kind of knew that we probably won’t see each other for some time now as he lives in Australia and I live in England but he said that he applied to a university in England so he might visit us a lot!

Me and my mom somehow got into a conversation relating to that family and long story short, I found out that me and him are related - not closely related but we are still related.
He’s my mom’s cousins son. Of course I never knew that at the time because no one told me and I’ve never met him ever and never even knew he existed.
I feel so wrong right now