On a 130mm wide saddle after a long ride my lower right back hurt and my right sit bone hurt. Left side was all ok.
I measured my sit bones - 125mm - decided the 130mm saddle was too narrow and switched to the only other saddle I have available (for the moment).
On a 134mm wide saddle back pain and sit bone pain gone and I felt more stable and more supported.
Lazily, I always adjust my saddle height by using my right leg as a reference. When the crank arm is in line with the seat tube, I position my heel on the pedal and try to see if I can lift up off the saddle and raise the saddle until I cannot lift up. Suspecting I have some asymmetry as evidenced by the sore right sit bone, I thought I'd try it with the left leg after adjusting for the right. Turns out I could lift up by about 5mm - 10mm or so (hard to measure). So it would seem to me that I have more effective leg length on the left.
Tonight, on the way home from work I decided to pay attention to my pedal strokes and noticed I drop my right heel whenever I'm coasting, but never the left at any time. I also only ever put my left foot down at stop lights and never the right. This too suggests to me that my left leg is effectively longer than the right.
Another thing...after loosening the brake levers so that they could move somewhat freely as I ride, the left settled lower. Related to that, I find I have a habit of sometimes riding with my left arm more extended than the right - I'll have the left on the bar end, while the right is on the bar. Though this could me a muscle memory thing from shifting.
One more thing....my saddle always ends up pointing slightly to the right after a ride.
Ok, one last thing I forgot. I have a history of piriformis syndrome on my right side. It acted up when I first got back on the bike a few months ago. It has since mostly subsided but I do get twinges from time to time when I'm on the bike for a while.
Wow, I really thought I was done....slight discomfort, I wouldn't call it pain, behind the right knee, closer to the outside, from time to time.

I've done A LOT of googling and there is just way too much advice, some of it conflicting, so I thought I'd post here.

btw I absolutely cannot afford a professional bike fit.

Thoughts?