Help me with my hair and suggest me a treatment please

[Potterypot]

I am really behind when it comes to styling and hair treatments. I have frizzy hair with curls and they are prone to dryness. Last year when I was travelling abroad I visited a salon for haircut and they suggested me a fantastic protein treatment without formaldehyde which made my hair silky smooth but now slowly half of it is turning back to it's original and dryer form and it needs lot of straightening.

Can you please suggest me any treatment to make them softer and straight against without much harmful chemicals or probably less chemicals?

Bump

Lush have some good treatments

You could ditch the straightening and embrace your curls/waves? Lots online about the Curly Girl Method - I do a diluted version and my hair is way healthier than it was when I straightened.
For a good protein conditioner, I use the Curlsmith Multi-tasking conditioner 👍🏼

@PressPauseontheMenopause My hair is a quarter curly and rest straight so do look kind of funny and the British weather doesn't help . It's a lot of work when I was curly besides I have a skin condition which makes matters worse hence the post .

This might be useful
https://www.allure.com/story/keratin-hair-smoothing-treatments

Thanks this is so helpful

You want a ‘brazilian blow dry’ which if done in the UK usually doesn’t have the very nasty chemicals. Prices in my town are £80-300. The £80 only lasted a month though.

Thank you @EmeraldDuck that's so helpful.