Carbs vs High Protein?

I’m recently diagnosed and very much still figuring out what my body is doing or feeling at any given moment - getting better at it, but still feel clueless 80% of the time. Hoping maybe someone has insight or language to help me!

My doctors tell me a high protein diet is better for EDS, but prior to diagnosis I’ve always found I best tolerate a bland, high carb diet. I’m already planning on speaking with my doctors about this, but the last time I brought it up they told me to take DAO pills before eating to see if that remains true. So, I am taking DAO supplements/operating under the assumption I have MCAS, and these things are still true. Even with DAO, I feel like If I eat mostly protein, I find that I really can’t eat much before feeling full or sick, and I feel more exhausted or nauseous during digestion.

Is this an experience anyone else has? Or can anyone guess what might be happening here? Is there something I’m misinterpreting about my body’s signals?