Could the rice protein be the problem?

I just can't figure out what's going on with my hair anymore. 3B, low porosity, dry, frizzy, thinning, and shedding. I am certain some of the thinning and shedding comes from Vitamin D and B deficiency, which I am trying to work on I am just terrible with taking vitamins etc, but I feel like this has been going on longer. I've been using the NYM Curl Talk Shampoo and Conditioner with the rice protein for 2, maybe 3 years. I've loved it, truly, it's managed my curls and avoided me looking like a soft poodle, but I have to wash my hair every two days because it gets dry and frizzy and anything longer I might start getting tangled. I try adding a hair oil for in-between wash days and it just kind of sits on top. My hair line is thinner and breakage is more frequent. When I do my once a month clarifying Shampoo and do a full on detangle and brush there's just so much hair coming off my brush/comb it scares me.

I have a derm appointment in November, but it's for late November and the wait is making me anxious. I know I'm vitamin deficient, but what if I've made it worse with protein overload?

Side note: I do have hard water but I have a shower filter for that which has helped

NYM seems to have discontinued their Curl Talk shampoo and conditioner but I found a seller on Amazon who was selling both in a pack so I bought two because I really love the stuff, that will last me awhile before I have to figure out what I'm going to try next. At the moment protein overload is the answer I keep coming back too and I'm contemplating canceling the order.

Routine: NYM Curl Talk Shampoo + conditioner, NYM leave-in spray, Herbal Essences mousse for curly hair, 10-15 minutes in a curly hair towel, air dry the rest of the way. Once a month Ion hard water Shampoo and conditioner for clarifying.

I use a basic combination and detangling brush with soft bristles for gentle detangling.

I sleep with a satin bonnet and satin pillow cases