Mental Health Support

I would conjecture that the real purpose of all this is control. Control of you, control of the situation. It's not that she thinks you are stupid, it's that she thinks you are not cooperating and need to be put in your place. And if you confronted her with that she would probably deny it until the Sun goes nova. In my family the dynamic was that Mom was the control freak and Dad was just ferociously devoted to her and willing to do whatever she wanted without question. Now that Mom is gone other family members have begun to sheepishly admit what a bossy and intolerable woman my mother was, and to this day my Dad can't see it. The problem I think you have is that it's escalating. The whole gifts/no gifts out of nowhere thing is an attempt to establish control by making it impossible for anyone to actually understand what is required of them, and providing an excuse for dominance and chastisement no matter what you do. This is not to say that my solution is the only one available to you, but you need to at least understand it might be, and understand the problem well enough to find something that does release you from their grip.