In that case you have the following options:
1) Officially renounce your PR status and apply again from scratch.
2) Obtain a US visitor visa, travel to the US and then try to re-enter Canada through a land border (using a private vehicle)without being reported for failing to meet the residency obligation. If you are able to enter Canada without being reported, then you will need to live in Canada for two years without leaving before you will be able to apply to renew your PR card. If you are reported at the border, you will have to appear at a hearing to argue why you should be able to keep your status. Given you've effectively spend no time in Canada, I think the chances are very high the hearing will go against you and your PR status will be revoked and you'll be asked to leave Canada.
3) Apply for a PR Travel Document from outside of Canada under H&C. You will have to provide very strong proof covering all of the last six years to demonstrate why you were unable to move to Canada due to your father's illness. I you are the only living relative he has in his country - there is some chance you may be successful. But again, you will have to provide proof of his illness. If the PRTD is approved, you can then move to Canada.