If your new growth is not healthy I would head to your doctor and/ or review your diet and lifestyle. Six months is not long enough to visibly damage virgin hair with an ordinary shampoo routine. What temperature is your flat iron? Is your hair bone dry when you straighten, ideally washed the day before?
THE NATURAL HAVEN: Straightening Facts :How hot is too hot?
THE NATURAL HAVEN: Heat on Wet Hair = Bubble Hair
permanents do not contain PPD, they are just colour molecules in a base mande up of the same conditioning agents (fatty alcohols and cationic surfactants) as in regular conditioner. PPD is in demi
permanent and permanent dyes. The Redken is a demi permanent so does contain low vol peroxide which is damaging if used regularly. Feeling and looking conditioned after is not the same as being healthy, these sort of products are often loaded with silicones and proteins.
Your hair is not dry and damaged without silicones, it is dry and damaged period unfortunately. Silicones disguise damage with faux shine and slip they do not 'nourish' or 'repair' hair. They do afford an element of protection from heat styling and from weathering or mechanical damage (brushing, hair rubbing against hair, clothing or your car headrest). Some can also build up causing as many problems as they solve, and can need shampoo to remove them which again is damaging.
Nobody can tell you what you should do, it's your call whether the true underlying health of your hair is the most important or whether you are satisfied with the appearance and feel of health that shampoo and silicones are currently giving you. It's not just teens who want to feel confident or fit in, people don't fundamentally change their personalities when they get a few years older! There are many teens embracing their curls or transitioning to natural on forums, if you find them you will 'fit it'. Some of the girls are converting their friends so they are leading the trends not being sheep!
Many of us here spent years or decades fighting our natural texture, never having 'good hair' because we had to fry it to achieve the look we wanted. If we could tell you how to make your hair long, straight, brown and healthy we would but it is impossible. I spent two years growing out damaged hair from colour treating and generally being rough on my hair, the only short cut to health would have been a pixie. I did loads of research and learned which ingredients work, what could and could not be achieved. Personally I got to the stage where I accepted commercial shampoos and conditioners and techniques were never going to give me the hair I desired so I was open minded to giving the Curly Girl method a year of my life before I decided where to go next.
Sulphates in shampoos thin the skin and can cause irritation, which leads to the skin pumping out more sebum. Dry shampoos like Batiste are very effective, just wipe off the excess with a microfibre towel. Many baby shampoos are sulphate free but a high pH to make them 'no tears' this is not good for hair. The other option is conditioner only washing which is super gentle.
If you are sunbathing be sure to use a hat or bandana that is proven UV protective, a regular hat will not keep all the UV rays out. Also be super gentle on you hair in other ways, sleep on a satin pillowcase, finger detangle when your hair is drenched in conditioner only, don't rip a brush or comb through it, use protective styling (gentle up dos).