Speaking from experience, there is next to no assistance available for responders. There is a new group called "Sheepdogs" that claims to be specifically set up to help first responders and veterans with PTSD, depression, anxiety or any other problem. They also reach out to perform disaster relief since their members are already trained and ready to go. I tried three times to get help from them with no response at all. I looked for PTSD groups in my area but since I am not a veteran, there are none available. My favorite questions when I am looking for assistance are "what branch did you serve in?" and "what could possibly have been that bad?" Lesson learned. I'm on my own.
As for the numbers, there are many things that skew them. I feel certain that the problem in Canada is farther reaching than anyone suspects since suicides are not technically LODDs. I know of two in my area over the last five years, but many more left the business permanently damaged. I know one that disintegrated on a call. I was not present, but those that were said that there didn't seem to be anything special about it. No fatalities, no grisly scene, no kids, just a minor traffic accident. To this day, we don't fully know or understand why a responder that was by all accounts, happy, healthy, and strong just quit mid call. Thankfully, he was a FF, so he got a medical retirement. To this day, he has nothing to do with any of us he worked with for many years. I have known several others that have left in a less dramatic fashion, but simply stated that they couldn't do it anymore. Those that leave, don't count in the suicide numbers since they weren't on the job at the time.
This business still has a hero complex, it hides what doesn't fit the image. Personally, I have never felt like a hero. I'm just a shmoe doing a job that was appealing at one time but now I'm too old and under-trained to do anything else, so I stay. Don't take that wrong, I am still committed to being the best that I can, but given the opportunity, I would leave in a heartbeat.