I bought a $20 water filter for our shower head and it solved all my hair problems (dry scalp included). When I think of how much money I spent trying various products by comparison, when I could have just bought a water filter... Innersense, Zotos, Jessicurl, shampoo bars, ACV rinse, DIY scalp scrubs... oh well, can't go back. It's this water filter:
https://www.amazon.com/dp/B001CDXMT0?psc=1&ref=ppx\_yo2ov\_dt\_b\_product\_details
I've tried a bunch of products from the companies you mentioned and many of their products have proteins. I forgot to add this article post to my first comment, it's really informative and so are the comments under the article.
I personally have problems even with aloe vera gel/extract and certain nut oils. Even avocado oil makes my hair brittle but I only really figured that out by trying the ingredients on their own. Every head of hair is different. Some people can tolerate certain proteins on a regular basis but not others.
More info about proteins in hair products: 1, 2
OMG if you have hard water, you NEED to get a shower filter. I really think it will help your hair alot. This is the one I used to use. It's pretty simple to hook up and it's easily available at Home Depot.
Oh if you tried grapeseed oil and your hair didn't like it, then definitely stick to argan oil! My hair loves Argan Oil too. It's a great one for protein sensitive and low porosity hair.