Help I’m freaking out

My last pregnancy I had a missed miscarriage so everything freaks me out now and I worry about everything.

Buuut my heart rate has been consistently high/jumping at work cause obviously I’m busy. Now today it hasn’t been jumping or been as high as it has been the past few weeks and I’m freaking out that means something is wrong?

I’m only 8 weeks today if that helps or if my heart rate is supposed to settle down now.

EDIT: I live in the U.K. so they won’t give me a scan unless I’m bleeding / cramping ☹️