You have tried everything from cheap to expensive moisturizers, creams, butters etc but if nothing seems to work then you need to ask yourself:

•  HOW you apply them ( in sections, after wash day, diluted, mixed with other products etc) 
• WHAT it gives your hair (protein, silicon, water, alcohol, glycerin, keratin etc)
• WHEN you are supposed to apply it (wet, dry, damp, moist hair etc)
• WHY you need it (moisturizing and/or strengthening,anti-breakage, softening , repairing etc)
• WHY NOT to use it ( protein sensitive, low/high porosity, oily, dandruff, fine hair etc)

I always suggest to do it yourself if possible because then you know exactly what the ingredients are. In case you get the opposite effect then you can investigate in the ingredients and replace and/or remove any ingredient until it works for you. 

DIY moisturizing hair spritz

DIY whipped Shea butter - Old recipe

DIY whipped Shea butter - New recipe

The spritz can be used on any hair types and hairstyles when it comes to the whipped Shea butter I personally make it to suit my skin, but I have seen many people using Shea butter on their hair with great results. In case you want to buy instead then two substitutes for the DIY that I have also tried/used myself is Creme of Nature Argan oil Leave-in conditioner spray and ORS Olive Oil Incredibly Rich Moisturizing Hair Lotion .