Cammiecam so sorry to here about your issues with the two step process. I was wondering how much water you were using in your henna? It draws water so make sure that your mix is like stirred yogurt especially if you are only using water in your mix. You can also put some coconut oil on your hair before you apply the henna to prevent dryness. Let it soak in as long as possible first. It won't stop the color from taking.
I wonder why it made your hair so tangled. Did you make sure that you didn't scrunch your hair up while you were rinsing the powders out? Did you let the conditioner sit on your hair and soften your strands up before you starting detangling?