you can only be sponsored by your partner if you qualify as common-law : living together for at least 12 months. You can not count the time where you were dating towards that. You will have to be able to prove that you have been living together for 12 months to qualify.
You can not be sponsored if you don't have a status in Canada - at least that's my understanding.
For inland, that's what it states in the guideline:
For the principal applicant and his or her dependent children
Passport
Passport pages showing the following information:
name,
date of birth,
issue and expiry dates,
the stamp made by a Canadian authority showing your most recent entry into Canada.
Format: Photocopies
Immigration document confirming your status in Canada
Examples:
visitor visa,
study permit,
work permit,
temporary resident permit (TRP),
document proving that you have legal status in Canada.
Format: Photocopies
the person needs first to get a status in Canada and then be sponsored inland - once the sponsorship has started the person gets implied status and no longer needs to maintain a legal status in Canada, but it needs to be there in the first place.
At least - that's my understanding of the guideline.
For outland, you also need to maintain a valid status in Canada, or apply when you are outside of Canada.
now - you have been out of status for a long time. I think your best bet would be to leave the country before you get caught - if you get deported, it will make it much harder to come back to Canada and it will be a red flag on your application.
I'm not sure what the best solution is, and I think you need a lawyer, as you need legal advice.
I would say that to do thing correctly, you should : finalise your divorce, get married to your current partner, and leave the country.( not necessarily in that order - finalise your divorce, leave the country, and have your current partner come to your country, or a third country if you can not get married in your own country, and get married to him). Then apply as married couple, outland, and wait for the PR to be issued to come back to Canada. If you leave voluntarily before being caught and deported, it will be easier to come back.
Otherwise, you will have to apply for an ARC - Authorisation to Return to Canada, and it will delay your file + add a red flag to your PR application.
Maybe other senior members can offer more advice.
Good luck,
Sweden