I'm sorry that all this "parts" business is causing you pain and confusion. I know how that is because I overthink and obsess about things too. I want the definitive answer to things, when often there ISN'T ANY!!!

My T says not to figure things out. It's good advice when your head is spinning, I think. What matters is your getting better, not whether accepting parts is right or wrong. I agree that your T is the one to help you with your questions and concerns about it.