Why was there no notice in advance that I would no longer be able to be able to ask questions?
I have Cognitive impairment.
I really do my best.
When you posted this message 5 hours ago, you were under a system-imposed question posting block.
The system has mechanisms to detect well-received vs. non-well-received answers and questions, as well as accounts (which are the recipient of such posting blocks). It looks like, according to this, you encountered a system-imposed block approximately 5 hours ago.
The system doesn't show any current blocks on posting for you, nor is there any way for moderators to control the system's automatic blocking / unblocking.
Such system imposed restrictions don't send notifications to the user until they encounter the block. Neither moderators nor SE staff can do anything with system-imposed block behavior.