I've had my hair highlighted for the first time ever.. tips please

[Sonolanona]

I've being going grey for nearly 7 years, but it isn't going white.. stuck at salt and pepper, so I gave in and went for highlights to blend it a bit. They look nice, and overall I'm quite happy with them (less so with the cut but still!)
I DO dry my hair as it's thick and I usually straighten it, otherwise I have wild wooly frizzy hair.
My new hair feels ok, but not as smooth as my virgin hair was. Other than purple shampoo/conditioner every so often, how do I maintain it best, bearing in mind it will be dried and staightened twice a week. It's just above shoulder length and I'd like to grow it a little longer.

Olaplex is supposed to repair broken hair bonds caused by colour treatment and using heated tools. Philip Kingsley Elastisizer comes highly recommended too and I've used it and quite like it. I used to paste coconut oil on mine and leave that in overnight when I used to bleach my hair. Treatments will only go so far though. I have highlights and have had them for 3 years now (I get them done every 10 weeks) but I am getting to the stage where I need to rest my hair due to breakage and hair loss which comes with any type of bleaching. Definitely use purple products sparingly as they can be quite drying

Fenty the come back kid is quite good I had it in an advent calendar and was pleased with the results .Otherwise have you tried any of the hair oils . They help my highlighted hair . Have also heard K18 hair leave in hair serum works although I have yet to try it.

I have similar hair that's highlighted & frizzy. I get on better with a spray on conditioner like Indola. And I run a few drops of Olaplex oil through my hair to stop the frizz.