You have gone down the right path! I started when I lost my job, had to sell my car to live on the cash, was broke as a joke. Been scared of heights all my life so a window cleaner was the last thing I thought I would become, didn't let it stop me.
Off I went with my bucket and ladder, on foot. Didn't even know how to trad.
Today I have a 2 man setup in my van, for me and my wife. All paid for by window cleaning, we work 2-3 days a week, I'm not saying how much we earn but we don't need to work any more than that and have the rest of the time with the kids.
I no longer look for work, work looks for me. You have to know how to be with the customers is the best advice I can give you, if they like you as a person then your in!
Be polite, bucket loads of respect for them and there property. Go the extra mile now and again, give them something for nothing. Be complimentary(cheesy but works a treat if done right) take complaints seriously, make sure they're satisfied with your work. Be regular, let them know if your not going to be on time,, some people hate not knowing.
You can make this work as many before you have.
Get in touch with local window cleaners(good ones) and ask to go cleaning with them, I did, and learned a lot.
If there's anything I can do to help you then I defiantly will mate.
I'm sorry to hear about your son, keep him in mind when the going gets tough
As it always does.
The very best of luck to you.