Bond repair recommendations?

I have long, glass like brittle 1a hair. It snaps and tangles easily and is quite dry, altough I don’t color or use heat. I use silicone free shampoo and conditioner (to avoid hair loss and keep it little more voluminous), mask once a week and sebastian dark oil on the ends every day. I was going to purchace olaplex no 3, but some reviews said it really can destroy hair that is already dry and is more suitable to heavily treated hair. What do other fine hair people use? Is there any bonding treatments suitable especially for us?