Ok. First I'd suggest a gentler poo, like one by Shea Moisture. I adore SM's retention poo. It's divine.
But I'm also wondering if you have protein sensitivity?
Have you tried co-washing? I know that sounds nuts, given your scalp issues, but it sounds like your hair is dry and your scalp is producing extra oil to try and compensate. If you find it doesn't clean your scalp well enough (and you do have to massage your scalp when you co-wash), try adding some brown sugar. (You can also add baking soda, but you'd need to follow with an ACV rinse, or add some ACV to your condish.)
That doesn't mean you don't ever get to low-poo, you might just do every other time. You might also consider using that co-wash to pre-poo. That will help keep your hair from getting stripped.
The other thing you might try if that doesn't seem to help is cutting out protein to see if that's your culprit.
So SM poo is an option. For a co-wash many of us use vo5 or suave naturals. One protein free one I have is Suave's clarifying condish. (Again you can add the brown sugar to further clean your scalp). For a RO (and you'll want to use one either way), I LOVE GVP's conditioning balm. It's very rich and moisturizing, and perhaps a bonus for you is that it's protein free.
Hope that helps a little!