kb656 said:
You probably don't want to hear this - but you need to leave the US and return home before you hit six months of overstay. You won't have Canadian PR by then - but you should still leave the US. Ideally you should leave now so that you don't get anywhere near the six month mark.
This is important because as soon as you hit six months of overstay, you are automatically given a three year ban from re-entering the US once you leave. If you have a year or more of overstay, the ban increases to 10 years.
If you end up with a ban, getting Canadian PR or citizenship will have no impact. You still won't be able to enter the US during the ban period and it will be very difficult for you to qualify for a visit visa once the ban is over. (It doesn't matter if you are from a visa exempt country now or if you get Canadian citizenship later. If you had a ban, you no longer qualify to enter the US based on your passport alone and must apply for a visa each time.)
The bans are a very very big deal and will impact your life greatly if you have family in the US who you want to visit. Again, I would extremely strongly recommend that you leave the US well before you hit six months of overstay.
Good luck.