You could try laser therapy through a good physio who specialised in post natal issues. I had terrible fissures after DD1 which gave me grief on and off for a year They miraculously disappeared once I stopped BFing. Must have had something to do with the hormones. I had them again with DD2 but it was nowhere near as bad as with DD1 and didn't last as long.

I wish I'd tried laser therapy (it works on cracked nipples so surely it's got to help) but I was too self conscious of how things looked down there - post birth, you get my drift. DD1 had a bout of constipation around 12 months which actually caused her to get a couple of fissures so I got my physio to do laser on hers and it did help them a lot.

I feel for you, fissures are awful. I found that the actual sensation of needing to go was worse than the actual act. Rectinal (? Rhoid cream) helped to numb things for me and a good diet with lots of water helped too.

I suspect I'm suffering with a prolapse now too but I'm yet to go to my GP to discuss it. One day, when I'm truly happy to leave my dignity at the door - forever! Lol!

Good luck, I hope you're feeling better soon.