check out the faq on spousal support here- lots of good advice there. Also the spousal support federal guidelines are great too.
http://www.justice.gc.ca/en/dept/pub...project/5.html
It looks like you would be paying him support. Like jlalex pointed out it is all about means and needs. It doesn't matter what he does with the money. With a long term marriage it is likely to be indefinate.
Perhaps if you live with your child who is still going to post secondary school -you can look into support for that?