Inspired by the comments here where people shared different things they have tried to ease the spasm pain, including positions, I started trying them all and experimenting with everything and anything I could think of. I was in so much pain I thought I had nothing to lose. Even tried drinking pickle juice - which seemed to do nothing but make me sick.
So far in these eight weeks I have been doing mostly stretching, yoga, breathing, relaxation exercises, pelvis stretching PT exercises, sitz baths, and foam rolling. Along with the usual gel applications. Most of these things seemed to help a little - but for me none really touched the long hours of intense spasm pain that would set in shortly after each bowel movement.
So I finally made a significant discovery after much trial and error. I'll describe it but it's much easier to understand visually, I'm linking to a picture I found and quickly modified to show how I set up each day.
Essentially I found out that for me if I essentially invert myself on a thick foam mat while lyng down with my knees bent in the air and feet floating below them, and then tilt just my pelvis even a more up from that inverted incline on a second firm cushion--when I find the right height and angle--the spasming calms significantly and sometimes stops entirely.
I have now added a small towel under my head to help reduce the blood all coming into my head and for comfort. Usually the spasm just keeps trying to happen on and off for many, many hours, but thankfully it's as if the spasms can't figure out how to take hold while being inverted. I think this makes sense in some way to me, the muscle system is disrupted by gravity and although the triggers are firing the mechanism can't complete fully. The pain for me is always at least cut in half and the spasm period window seems to be slightly shorter.
Some days it takes a little figuring out how to get this to happen, I have to keep adjusting the height and angle of my pelvis if the spasming starts kick in strong, and then I know I've got it right when I feel a release through my pelvic floor and the pain goes down immediately. I keep deep breathing this whole time and focusing on relaxing breath through the pelvis floor muscles.
See the picture link, it's probably much easier to understand that way. It's just an edited rehab picture I borrowed.
Anyways, I have been doing this for a little over a week, and during this time the fissure has definitely made some real progress for the first time, at least the pain is finally not so bad. I hope that in time the fissure will heal due to much less spasming cutting off the healing. Now, my next issue to deal with is constipation for the first time in my life - going to try the advice in some posts here and try reducing my fiber intake, which was already really high before I started trying to add even more fiber on medical advice. Magnesium is helping.
A minor note of caution. I have read that being truly upside down for long periods of time can be truly dangerous due to pooling of blood in the head and heart, and even the lungs do not like to be upside down and this can be dangerous for them. So while this is not a fully upside down position, you can feel it has real effects on the system and especially the blood flow to the upper torso. So for safety I take a break and get up about every hour and walk around until I feel normal. And the spasming often has started to set back in by then, so I'm relieved to lie back down semi-inverted. I put a laptop on my knees and watch movies or work.
If you give it a try, play around with it, you may have to find your own version of this to disrupt the spasm mechanism, I truly hope that it will work for some folks here.