Hi Elizabeth,
That letter is written in Rusyn, definite Lemko dialect (with some 'rusynized' Polish words). Only the sender address on envelope's back and at the letter end are in Polish. It was sent from Legnica region, Lower Silesia (north of CZ-PL border). The author in 1947 is using both new PL Wroclaw and wrong GER Brieslaw (should be Breslau) province center names.
Google translate won't be able to process it. I can try to help you deciphering the content.
Cheers,
Petro Z