I've had anxiety for years but sometimes I just get like bad anxiety/panic attacks triggered from wanting to go back and wishing I had done something different.

I am currently in a bad bout of anxiety since yesterday. It's so dumb, recently reached back out to someone on an online platform, we had talked about dating and stuff(we were from the same area), but life got in the way and I just wasn't available emotionally and had some serious stuff to deal with. Dad has an immune system cancer and was being treated during the biggest wave of covid we had, so even if I wanted I couldn't take the risk too meet random people that don't adhere to the rules of our family bubble. So we stopped talking over the winter. Our convo just never started back up after one day. I reached back out recently since both my mental health and dad is doing better and almost finished recovering from treatments, but then bam realized they aren't online anymore after sending my message. So now I can't stop thinking I missed my chance. Why didn't I reach back out sooner? Should I have said something? I didn't want to bum them out with my sob story. Why did they not send me a message? I hadn't thought about this until now. And well I just figured they would still be around. God I suck at relationships.

This is not the first time I feel like this over a relationship or bad performance at school. I keep thinking I should have done X instead of Y and it consumes my thoughts. 

So thoughts my anxious peeps? 

I'm just sitting here like I feel like shit since yesterday over this even thought I know it's now out of my control now and I should just get over it and move on.