Welcome to the world of fissures! Just about everything about these suckers is counter-intuitive! The surgerical solution for chronic fissures is a lateral internal sphincterotomy - so a cut is made in the ass to heal a cut in the ass. :D
Same with the ointments - we want more blood flow to heal a cut that bleeds. Its weird, but it works. You need a script from a doc to get these ointments, but any GP in Canada should be able to prescribe them for you. The one problem you may have is that few GPs have any clue about fissures, which is why they prescribe hemmie ointments so often, which cause more problems. You need nitro at 0.2% or diltiazem at 2%. Make sure the doc understands that - I was first prescribed 2% nitro which was way too high. I got that prescription from a doc in ER. At first he didn't believe me when I told him that nitro was used for fissures, and then he went and looked it up, but got the concentration wrong. A good GP will know better, though. My new doc knows what to prescribe. You definitely can't get these OTC - they are actually also for heart conditions. There are side-effects: specifically headaches with the nitro, and some dizziness, because it dialates the blood vessels. Generally, though, the headaches and dizziness pass once you get accustomed to the meds. But these side-effects are why it's important to get the right concentration. Whereabouts in Canada are you, BTW?
There are lots of folks here who suffered with fissues for months and even years. I had mine for about four months when it was really bad, but about a year altogether off and on (it would heal and it often retear - the whole time the docs kept telling me I had hemorrhoids and gave me the wrong meds!). Seriously, get on this asap - fissures tend to get a lot worse and they are very difficult to heal without surgery once they are chronic. Now, if yours does become chronic and you must face surgery, don't despair. The surgery is not too bad. It's not fun, but it isn't as bad as it sounds, and it's given many of us our lives back. I had surgery for my fissure in May and it definitely gave me my life back.