Lars,
I could feel your pain this am, but had to go out of town for an appointment with my therapist. Check out this website: heartmath.com and start practicing meditation and deep breathing. It can only help you. Today my therapist showed me on the computer how out of sync my body was when I was talking about how golfing stresses me out (that I don't play better). And then I practiced the deep breathing technique and could see for myself how I improved. It actually brought tears to my eyes as I saw on the computer for the first time the intro to the hearmath technique (even though I have been practicing it for many months). An MD doc and a PhD doc were talking about the science behind the technique. Heart/mind/body are all one. I got teary-eyed because I have been my own worst enemy at times in spite of running to all kinds of doctors to get a fix for my digestive problems.
Hang in there. You will get over this problem and get a girlfriend and have a family (if that is what you want).
Cheryl

Although I am like you and wouldn't or couldn't use the nitro because of the headaches, the headaches do generally get better over time, and it takes time for the nitro to really begin to help, two or three weeks, I think...

Nitro gave me mild headache and not always. Tylenol took care of it
very efficiently if I needed it. It did help immediately with the spasm
pains but fissure needs 3-12 weeks to heal anyway, so, yeah, one can see first visible improvement in couple of weeks , same as with the LIS. You have LIS and than you still have to heal your fissure, which can take many weeks. I healed my first fissure with Nitro, but after couple of weeks I got off my MOM and mineral oils as advised by my CRS and my fissure came back : (((. Wish I had this wisdom a year ago - but yet- don't we all ...

Lars, Thats a shame the nitro gave you a headache !
Dilitazem helped me through without headches, maybe this could be a option for you !
Take care

nifedipin worked better than nirto for me and better yet it dod not give me headaches.

Dilitazem helped me through without headches also. Maybe you could try that?????
Cheryl

perhaps if you want to try the nitro again, use a very smaller initial dose and work your way up.

To add to what Gareth suggested, the headaches are transitory, not long-lasting, and like the nefedipine and diltiazem, takes time to work. In fact, most approaches in treatment require patience and time...Botox is another example.

that's a good point kim.
it seems that when it comes to fissure and ass pain, we all want relief INSTANTANEOUSLY. and while we want whatever we are taking or applying for the butt to quickly work, it definitely takes time to work its magic.
healing a fissure has an inconsistent path of ups and downs.
there is nothing that takes away a fissure overnight.

Is Dilitazem and nifedipin creams like nitro or is it gel based?