CPPD and LTD are income replacement benefits your ex receives due to the fact that he is permanently disabled and unable to return to work. You are not entitled to any of those, other than the fact that those would now be considered his income for support purposes.
Although CPPD didn't start until years after the accident, they backdate the start date up to 3 years. Similar to Ontario Works, CPPD is deducted dollar for dollar from LTD. His monthly payments now are his income and that is what he is paying you CS based on. Once a settlement occurs, he would have to properly invest the settlement and the gains earned from that would then become his income for support purposes moving forward. Any settlement for the Personal Care costs would continue to be exempt. If there is a tort claim, only then you may be entitled to a certain part of that settlement.
You said he is being paid over $2500/month for attendant care/housekeeping which does not count as income. This is true, as it is not his income. The insurance company would have met with both of you at the beginning to determine what his needs are (ie what you have to do for him) and therefore how much benefits he should receive. Now that you no longer do those services, the insurance company would have had to met with the new service providers to ensure the work is being done.
Although you claim you have no education and never worked, the reality is that you worked for 5 years as an attendant care provider, making a pretty good wage at over $30k per year tax free (around $40k gross). Therefore, you have great experience for your resume that would help get you another job no problem as someone else's service provider, working at an old age home, housekeeping, etc.
Blaming your ex for your osteoporosis seems illogical. However, people with that and other worse diseases are still able to work. If it is your claim that you can not work, then you need to be on CPPD yourself. Without that, court will imputed an income of most likely the $40k you have been making for the past 5 years, so that you can help support your kids as well.
A bad marriage followed by the divorce process is a stressful and depressing experience for everyone. It's time to get your life back in order, take care of your health, and become independent again. Trying to take away (half, all, or even a little) of a disabled persons only possible revenue source for life, apart from the cs, is wrong. He's only receiving $3500/month so it's not like he's living large. You both have been making approximately the same income for the past 5 years.
The marriage is over. IMO, it's time to find a new revenue source.
Good luck!