Chemical free products are better for your skin
Water itself is a chemical, there is nothing as chemical free products.
If a skincare product burs, it means it is working
A little tingling is normal but stinging or burning is not normal. It means you could be having an allergic reaction.
If retinol irritates your skin, stop using it
If you feel any type of irritation, don't stop retinol entirely rather chnage how and when you're using it. Decrease the frequency of use to twice a week, then slowly increase as tolerated.
You should spend more for better skincare
The effectiveness of the ingredients and the formulation itself is what matters, not the price.
You need to keep changing your products to maintain healthy skin
Skincare products you have been using don't stop working for your skin after a period of time. Active ingredients generally take around 1-3 months to work. Continue using products that are working for you.