how would i go about accessing my deceased fathers accounts?

The executor of the estate will need to provide documents to the bank for accessing assets.

Boyfriend buys house Deed is in both our names Right to surviorship.Boyfriend passes away house goes to me.Loan only in deceases name.Does the estate have to pay off loan before they can settle estate? The estate has enough money to pay off debt and then have plenty left over.I live in Ma. I have been making payments on behalf of the estate.Bank sending statements to home address and is Adressed to The Estate of ---- Business account.
Which in the past it was only adressed to Joe Smith

This could get complicated so you should be working with the estate itself. Yes, the debt has to be paid. There is still a lien on the home and the lender wants to be paid. If not they'll have the option of taking the property.

If you are paying for the estate, they need to be aware of this.