Welcome to the forum. I'm sorry that you're suffering like this. In my experience, the pain of AF is unfortunately something that to some degree one has to learn to live with - there are different ways of doing that, though.
What I have found most effective is an anticonvulsant and neuropathic pain agent called
pregabalin (it's often sold as Lyrica), which I get on prescription from my GP. This doesn't actually remove the fissure pain entirely, but it reduces it a lot and makes it possible for me to live a normal life, at least for a while.
Others here have found that the anticonvulsant
gabapentin helps with the pain. I have no experience with gabapentin, so can't comment, but it seems to be an effective drug.
Proctosedyl suppositories can help, as well as nitro cream and ointment (GTN), and learning to relax the sphincter muscle can reduce the tightness that leads to spasms. At one time I found that an antispasmodic like buscopan would also help.
But the pain is something I never had before I got my first fissure two and a half years ago, and I've had to learn to tolerate it as part of my life - I don't think there's any way around it, except Botox and LIS surgery, either of which may or may not ease the problem.
You might also want to consider some sessions of counselling or psychotherapy - I find that a weekly hour with my therapist helps me to navigate my way through this painful and difficult condition. Hope you feel better soon.
David