I understand finding childcare is not simple, especially with an autistic child. I also know this will take a bit of time but it seems like you have little choice AT THIS TIME. While you are a wonderful mother there is no way to work, home school and be with your children during non-schooling hours. Not because you are not awesome but you have only have two arms and two legs!
When my H's cousin was diagnosed with autism (she was right around 2 years old) her parents contacted the Autism Society. It may be called something different in Canada but I bet there is a like organization. Not only did they find support groups and a true support system but they learned of so many resources including childcare. It may not hurt to seek out support from an organization to see what resources they have. Often times it seems other parents in the same boat are your best resource.
I know you don't want to hear any of this but right now it's just what you have to do. I just did a few quick Googles (childcare and your area) and I do see what a problem it is based on the few articles I read. However there must be some solution. I wish I had a solution for you but I don't. So we will just support you and encourage you until you find one.
I wonder if you procrastinate because you don't want things to change? I gather (and it's wonderful IMO) you really like being a SAHM and homeschooling your children. And now that will have to change for the time being. If you get your self employment up and running again that means things will be changing.
Change is scary but it can be good. It's hard to get started.
Since childcare is such an issue in your area have you considered taking on a child or two during the day for a working mother/father? If I understood the article I read correctly you can watch up to 2 children a day (outside of your own children) without have to obtain any sort of license. I realize having four children to care for each day is, well, A LOT!
I don't know really what the answer is. Just trying to brainstorm.
You have done LOTS of good work in the past 24 hours. Keep that in mind as you deal with this next set of hurdles.