u/Electrical-Shirt-117

The first two pics are from few months back ..and the other two are recent ones ...

Hello ..few months back i had straight hair with shine and volume and had that smooth texture ...

But since few months ..my hairs are all wavy ...gets frizzy and wavy even after applying conditioner (i have oiled my hair in the last pic which i took just now)..and the diameter of the hair strands is also getting lesser ...

I want my straight hair backkk.😭 Please share any tips how can i do so....🙏