Just got Danger Jones green done a few days ago. How fast does this fade?

So I recently had a hair appointment to get green hair. I've been going every 3 months, but I might not be able to afford getting it done again in 3 months, so I'll probably see how much I can let it fade until I get it done in October.

I was wondering how long this color will last if I wait until October (I wash 1x weekly with cold water and color safe shampoo, but will wait a few weeks before the first wash) and what it will look like as it fades?

Also, a side question: what products do you use/recommend to help with damaged hair?