There are a lot of things that you can eat that are supposed to help your memory but the best way is to develop a system just for you. Getting a planner, making to-do lists definitely help. You can also make small habit changes like if you need something the next day, put it by the door with something you wont forget, and if you remember something you need to do/take then do/take it straight away and don't say later. You can also set reminders/alerts with your phone.

You sound more disorganised than suffering from memory loss which is better cause being disorganised can be fixed!

I used to have this problem last time. One solution for me was i keep my keys together with my wallet instead of separately. So you connect the two. This way you only need to remember one thing/find for one thing.

My wallet has a zip so i just attach the key ring to the zip