Start from your own strength! You have a handicap and you know the kind of support someone like you need.
So do a simple game to help you remember things. Don't be too ambitious. Do something really simple that works and build it out in small stages, always keeping it working (google "agile" if you want to know more about this way of working). Perhaps look at memrise.com for inspiration and think about how you could enhance something like this for someone with your particular issues. Think of special areas, there is more to remembering then vocabulary(people, situations, sounds, music, procedures, short term vs long term) . Think about how in what way a game could support a particular problem YOU have.
When you have a prototype (even a simple one) you might be able to get support, since having the handicap yourself will give you a great story and in this way you can turn your handicap into a a real advantage. Perhaps you will even be able to partner with someone that can help you with the bits that are too specialized for you to do handle yourself. But to get that you first need a prototype game.
Most important of all. Have fun developing it and try to find someone you can show off when it works! We all need this! In this way everything else is a bonus.