I feel it isnt the shampoo that makes ur hair curly. To make your hair curly, the hair bonds have to be structurally changed through chemical means. Shampoo isn't capable of doing such at all else there wouldnt be perming and such processes out there in the first place. However, what explains your "curly" hair now then. I am guessing two possible reasons to your situation, which i did some googling to better explain it all.
Possibility #1: Stress damaged hair (
Hair pattern changing from thick to thin or straight to curly or stress-damaged hair)
Quoting from the article: "I always thought I had straight hair, not perfectly straight but reasonably straight. However I have noticed over the past three years that I had some “super curly hair” (as I have begun to call it)."
Perhaps what you are seeing right now is stress damaged hair. Again from the article, "This damage is likely due to pulling from brushes or combs that meet snarls or snags and stretch the hair when pulled on through.". This might be even made worse if the styling products left over in the hair is not removed properly which makes it harder for it to be raked through. This will then eventually result in the "curly" hair that you are seeing.
Possibility #2: Heat damaged hair (
Signs of Heat Damage & What You Can Do!)
If your natural hair texture is straight (most asians have straight hair too), and it fails to return back to the original state (what you're seeing now as "curly"), then your hair might be damaged. One possibility is due to heat. Direct heat appliances such as hairdryer, can actually damage your hair if used improperly.
Quoting from the article once again, "Direct heat appliances or tools can cause the cuticles of your strands to be stripped off or break away from the surrounding fibers. The explanation for this is because heat tools or appliances can literally instantly drain the moisture from your hair which can cause the outer layer (the cuticles) to expand and release moisture of your strands that were trapped in."
Of course, there might be other possibilities on top of the aforementioned possibilities too. I aint an expert on this anyway and all these can be retrieved from some researching too. It might be due to some chemical processes that you have undergone as well. The reason why its made to shown as your shampoo makes your hair curly is also probably because its too drying for your hair. As mentioned in the previous post, when your hair is dry, there is no moisture. When there is no moisture, your hair is dehydrated and will look dry and consequently, it makes the hair look "curly" too. As for the frizzy, it is often accompanied with damaged hair too. This means that your outermost layer of the hair (cuticle layer) is raised and not flat so that totally explains your frizzy hair.
Baseline is that IMO, your hair is definitely damaged. All kinds of symptoms are already shown. Dry and brittle hair. Frizzy hair. Susceptible to breakage. But i still feel that its not damaged from shampoo, of course. Most shampoos out there are suitable for everyone to use but the crux lies on finding the one that suits you and your hair type. Now this is my personal humble recommendation to you. I might be wrong so u can just take it with a pinch of salt.
#1: Get a moisturizing shampoo. Needless to say, your hair is too dry and not moisturized. If possible, get a pH balanced and moisturizing shampoo then that will helps even more. When you have moisture, your hair will have the added weight and it will tend to return back to the natural hair texture over time, if the situation is not serious. Yes, kanebo shampoo. I really recommend u to give it a try but of course, its up to you at the end of the day.
#2: Get some hair treatment products. Deep condition your hair by either using an extra moisturizing conditioner or hair masks (if you want it to be more effective). Deep conditioning treatments will give your hair a bit of a boost, add a little extra moisture and protect from frizz. Nigelle DS Tf Treatment is amazing IMO. It helped me to overcome my dry and damaged hair after perming.
#3: Be gentle to your hair. The yanking off part for GD is not normal IMO. When i use GD, the most i yank off is 2-3 strands of hair. So if you yanked off 10 strands of hair or so, do something to prevent it. At the end of the day, shampoos and other treatments can only help to reduce the damage and not totally cure it. The best way is prevention.