Your only options are those you make yourself. Amazon has not yet made any special agreements for FBM shipping with any carriers - only for FBA.

You can set up and account with a Canadian carrier. Canada Post is easy, but rates are pretty static unless you have sales history to justify more significant discounts. DHL, Fedex, Purolator, or UPS (and others) may be willing to have you a deal for the first few months, but that may be lost if you don’t have the volume.

If you have a Professional account, you can adjust what you charge for shipping, but customers are accustomed to free or low cost shipping, so you will need to set your price to include at least part of the shipping cost. You will also need to consider GST/HST and may need to consider PST depending on your location.

That referral fee does not cover shipping costs in any way. It is simply to address advertising and payment processing. Typically, it will cost your more than that to use other customer acquisition services and payment processing.

It is worth spending some time looking at what your competitors charge and compare with what your costs will be to determine if there is a opportunity to be profitable and competitive. If you can not be both, you should quit while you are not behind.

Dave