lost text messages after upgrade.please help

i upgraded from the Iphone 6 to the iphone 7, i always backed up, my iphone 6 was sold to the shop, my new iphone has 2 icloud accounts - the one im using now and the iphone 6. I cant seem to get my text messages back and i am upset because my wife passed away with cancer and all of her text messges have gone. is there any hope ? please help.