From what it sounds like to me you have two things going on
a) Since you haven't used any protein in a while, you hair is dry because it can't hold on to what ever moisture you are giving it in your usual conditioning. Hair CANNOT hold on to moisture if there is not suffiencent protein.
b) The dry weather is just making it worse.
Try this
a) condition with the motions cpr
b) Follow with a deep moisturizing conditioner for atleast 15 minutes
c) Make sure you use adequate amount of leave in conditioner to help seal in moisture. Don't be afraid to use a little oil on your hair as well to help your retain the newly add moisture.
Doing this should help stop the breakage by restoring both moisture and protein levels. Occlusive agents like silicone and oil help coat the hair to retain moisture. You don't have to use much, just small tad of a little light oil after you do your hair will do the trick. It will also help decrease breakage from manipulation by providing a smoother surface for you styling tools.
You should see improvements within 2-3 washes. The breakage did not happen overnight, it will not be fixed over night. Don't panic and use extra protein thinking that more is better. Too much protein is a much harder situation to correct than too much moisture. After doing this, your hair should start holding on to moisture better.