PLEASE HELP

I've posted in here before I'm sure, as I've been having an ongoing biting dilemma on-and-off for two years now. I still don't know what is biting me, but I'm almost positive they're bed bugs. However, I CANNOT find them. But this creature was just now crawling in my bed. I know It's not fat like bed bugs, but I see pictures of slimmer ones when I google them sometimes. What is this? An unfed nymph maybe?? Please help me - I've been losing my mind for years over these insanely itchy bites that come and go. Also, I apologize; these screenshots are of a video I took of it scurrying. It was very tiny.