The first place you went wrong was putting them in the freezer! Once coffee is roasted it needs to be placed in a sealed bag to age between 5 and 14 days to get the best results. Coffee is very delicate, It hates the cold/heat and sunlight. Keep then in a airtight container in the cupboard and only grind as you need. As ground coffee will go stale after 10-15 minutes after grinding and whole beans will go stale within 24 hours out of the bag.
Re roasting beans will not get them back to life. Best thing to do is toss them in the bin and start again. Blending coffee is an art form and takes many years of practise and kg too. start off with a nice base coffee like a brasil or a colombia and add 20% here and 10% there of other beans to get the flavour you want.
Hope this helps