@NCHairDiva
Here is what I would do if I were in your situation:
Since the hair is tangled and dry, I would focus on a "divide and conquer" thought process. Keep in mind this is something that you do not have to do all in one sitting nor would I advise it to be. Do it over a few days to a week and wear your wigs when you need to leave your house while you work on it.
Your first goal is to lubricate and stretch. This will allow a better environment to remove tangles.
1) Melt down your shea butter and slather it on your hair. Since the hair is tangled at the roots, don't try to force it by parting or sectioning. Instead gently gather it in one low ponytail and band it. Before putting it in the ponytail, pull the hair a bit at the base to stretch out the middle. Now put on a plastic cap to allow the butter to soak in. At least a few hours. Over the next few days, remove one band at a time, and remove tangles by separating the strands from each other. When you get to the base of the ponytail, this is where you can section into more ponytails and repeat the process.
Your next goal is to infuse moisture back into the strands.
2)Get your most moisturizing conditioner and apply it on top of the Shea butter and braid the section as you go to avoid more tangles. If you have a steamer, sit under it for 20 minutes. If not, just put on a plastic cap for a few hours, then rinse while in the braids. Apply leave in and seal hair with Shea butter all while in the braids. Put the braids back in a banded ponytail so they can dry in a stretched state.
Your final goal is to allow the hair to rest. Leave it alone for up to a week. I'm sure the pulling and tugging will also leave you with a pretty sore scalp so just give your hair and scalp time to recover.
The silver lining is you have learned what not to do and something that your hair doesn't care for. Protein is one tricky little rascal for chemical free hair. I believe all hair needs a protein kick here and there but too much of anything will eventually run it's course.
As for henna and all Ayurvedic powders, here is what I have learned:
What you mix them with DOES matter and changes how they react on your hair. I've always just mixed my henna with water and experienced well conditioned hair. This past treatment, I mixed with coconut milk and it felt like I just did a protein treatment.
Powders should always be applied to tangle free hair. If not, the powders will get caught within the tangles and make them even worse.
HTH!