Growing Out Bleached Hair

Greetings!

I have been a platinum blonde for 4-5 years now. My hair was as healthy as bleached hair could be until I stupidly decided to try heat tools (after being no-heat for almost my whole life). This caused irreversible damage to my otherwise "healthy" bleached hair. I am basically in mourning because I was so pleased with my hair until the heat damaged it.

My hair has never broken before - until the heat. I have not used heat for 2 years now. Still, my lengths are suffering, causing the newer growth to break further up.

Therefore I wonder what I might do. I have used Olaplex several times the past 4 years. I deep condition. I try not to overlap when doing my roots. Still, the healthy days seems to be gone forever.

I am considering doing something to make my roots blend nicely to the platinum when they grow out. My hair badly needs a long, long rest from any kind of bleach. Should I do a baylage, highlights, airtouch? I have no clue what is the healthiest/least damaging option. I would like to do it once and for all and not have to worry about the colour for some years.

Maybe I can go back to my favourite platinum colour again some day, but for now my hair needs only to rest and grow in peace. Any advice is appreciated.