Soey, I have also not had surgery. And I also have IBS. Your fissure is just going over into the chronic stage. I haven't looked at your other posts so don't know if you have been given something to help heal your fissure. If not, you should get something from your doctor - a calcium channel blocker or nitro (GTN). Suggest this to your doctor.
You said you no longer have the spasms; this basically means you
are healing. I know that fear of the spasms coming back feeling, knowing how incredibly painful they are. I had mine off and on for over 18 months, lost weight, etc., so have been there. Try not to worry too much. Don't overdo things. I tried Valium and it did nothing for me (I used to live in DK and know I would not have got that there...). I do take a very small dose of Lorazepam, to sleep, and am ever grateful to be able to sleep pain free with this.
I know that it is easy to say don't worry when I am not in your shoes, but it won't help you to heal, and that is what you have to keep uppermost in your mind.
Best of luck. Keep coming back. We are here to listen and to help