Advice on judging clearance solo?

After passing, I’m having really bad anxiety with judging clearance when passing oncoming traffic with parked cars half on the pavement and half off.

For example, coming home, a bus was oncoming, the SUV in front / large car in front passed with the bus on one side of them and a skip on the other.

My car is a little Aygo, but I got terrified of how close I was to the bus. I dropped my speed right down as I was going past it and the skip and basically crawled between them, checking left and right between the edge of my car, the bus, and the skip. The other car which was bigger than mine passed through no problem, why was I so scared / felt like I was going to hit my car on something?

I’m going to put a post it note in my car to remind myself to keep calm in these situations as I tend to panic.

I think some of it stems from early on in my learning journey, I clipped a mirror of a parked car, so have been overly cautious since.

Any tips? I also don’t want to unnecessarily stop traffic if there is room, but I am being overly hesitant. Just wondering if anybody has dealt with the same?