Hello, thank you for the question.
So you lived together for 5 1/2 years, that certainly counts as common law. By most definitions, a commonlaw relationship in ontario begins when a couple cohabits in a spousal relationship for three years, or immediately upon cohabitation if they have a child together.
So you'd certainly be treated as commonlaw by the court.
Property division is rather open ended in a commonlaw relationship. Unlike in the dissolve of a marriage, there are no automatic rights to any property owned by the other in a commonlaw relationship. However if you have contributed to the value of property owned by your former partner, either monetarily or by other contribution, then you can make a claim on that value. So if he started a successful company while you were together and you helped, you should be entitled to a share in its value. Of course, it depends on the nature of your contribution, so it comes down to the facts.
Spousal support is also certainly on the table after 5 1/2 years of cohabitation. You could go to mysupportcalculator.ca to get access to a free version of the spousal support guidelines. Play with the figures, enter the basic information, and see what results you get. There will be a range of amounts and durations of spousal support, which a judge will also look at as a guide.
Making a property claim after a commonlaw relationship can be complicated. I strongly encourage you get the help of a family law lawyer, so please find one near you and make an appointment. If you don't know any personally or by reputation then ask family and friends for a recommendation, or go to lexpert.ca, or to the Law Society of Upper Canada's website for its Lawyer Referral Service.
Is that a good start? I'll await your question or comment. If I've answered you fully then I'd appreciate a positive service rating please.