I'm currently working on a story in which every single person in a certain city gets amnesia simultaneously. Basically, before the start of the story, it was a town where a subset of the population had psychic powers, and these were widely acknowledged and made use of. A group of non-powered villains decide that it'll be easier for them to accomplish their goals if no one has psychic powers anymore, so they design a magical bomb to destroy psychic abilities. Unfortunately, the bomb turns out to have a bigger impact than intended - everyone loses all long-term episodic memory, and anyone with psychic powers or who've had their mind altered by psychic powers ends up with serious mental disabilities. So far, I have a group of people getting everyone to meet up at a certain landmark so they can figure out who has valuable skills (because procedural memory is unaffected) and assign them the appropriate jobs to ensure that as many people as possible survive. The protagonist ends up becoming one of the caregivers for the disabled people, because she mistakenly thinks her brain-injured psychic younger brother had a preexisting mental disability, which would suggest that she has experience caring for disabled people. (She thinks this because he's wearing a diaper, which is actually because he's a bedwetter.) What would be some other issues faced by the setting?
You're already extrapolating consequences, so just keep doing so. It's your story, and you're doing just what writers do - set a premise and decide what the consequences would be. As you start writing, you'll undoubtedly come up with others. Don't get into the habit of running to others to build your story for you. Trust your imagination, and exercise it regularly!
There is a manga that is similar in that, a. there is a bomb that wipes people's memories and b. some people end up with mental disabilities from it. (Don't worry, plot wise its entirely different from your story.) It might be good for inspiration though, in regards to issues that could arise from that type of situation. It's called Zennou No Noa. I'm not sure if I'm allowed to post links, I can PM you it though if you want.
Some thoughts to add conflict: -So, the non-powered villains became the good guys, and one of them might even become some sort of leader. He is respected and all, but what if his and others' memories start coming back. -Alternatively, what if there is only one person whose memory comes back or may be his memory was not affected by the bomb in the first place. Just some thoughts which might not be useful at all to you Good luck.