I feel for you, I cringe thinking back of the pain. I had a fissure after my daughter was born. The pain killers made me so constipated and nobody really warned me, anyhow...... The pain was so bad, I would cry and cry and had to sit on ice packs for hours on end. After a bm it would take several hours for the spasms to stop. It took a very long time for anybody to figure it out, several months actually. Anyway, I finally saw a rectal surgeon that I had seen previously and he fixed me in days. He is a miracle worker. He prescribed a nitro glycerine salve that the hospital pharmacy makes special, it's also for angina patients, it's a muscle relaxant. Anyway, it worked within days I was pain free. I couldn't believe it. I have to say absolutely nothing else worked for me. Again, I have felt your pain and it is excruciating. I would scream at the top of my lungs in the car cause I couldn't bear to sit if I wasn't on ice and I had a newborn and a two year old to take care of, it was pure hell...
I wish you the best... oh, I forgot, there is an anal fissure help page. I think that's what it's called, it's been 5 years almost, but try that in a search engine, that was very helpful. Surprising how many people have had fissures.