Why is this freaking me out?

Okdi bare with me as I’m actually not sure what’s happening right now. My anxiety has honestly been great over this past month but something so small has happened tonight that freaking me out.

I was fast asleep in bed and whilst asleep I felt a sharp pain in my leg(thigh) which I guess woke me up. So I initially thought it was a bad dream but after rubbing my leg where it was sore there was a little scratch like line feeling and when looking it looked like something had scratched/but me there whilst I was asleep.

I live in the uk so what are the chances something poisoness has bitten me?

My husband sleeps next to me and I think the cat was on the bed, but he never sleeps under the cover so I’m 99% sure it’s not him.

How can something like this send my anxiety crazy????