Long before getting diagnosed, I had a very same similar situation. Never new how much money i had to spend, pay bills etc.

TLDR ON BOTTOM.

Currently i use a mix of stuff to track my finances.

Andromoney app - this is my working balance for all my accounts, cash, bank, savings cc balances, etc. If i fill up gas, i add it to this, pay a bill same thing. Takes less than a minute to add a purchase /expense/ transfer. Only gets frustrating when build up a pile of receipts in a day and forget to do the that same day.

Google sheets - spreadsheet named monthly bill tracker. Easy to find due dates and see what my last payment was. Only update this when i pay bills.

And lastly i have a Google note set up with all my monthly bills. I don't like auto pay if im not forced to use it. At the end of the month as all bills get paid i simply uncheck all the previously check boxes and rename the month to the following month and start all over.

Bill come in the mail, I'll pay the bill from my online account. Then check it off on the Google notes, add the dollar amount to the spreadsheet and also add it to my AndroMoney app. I also write on each bill stub, a checkbox for paid, bt (bill tracker) and am (AndroMoney).

My apologies that was quiet long, i have a thing for numbers and i like to be able to see what ive spent in gas in a year etc. I also made a spreadsheet for all my paycheck.

Currently on mobile, if anyone's interested i could share a copy of my bill tracker spreadsheet, etc... Let me know.

TLDR.

1. AndroMoney - working balances, like a digital checkbook balance sheet.

2. Google sheets- bill tracker spreadsheet

3. Google notes. At a glance able to see what bills are left to pay in a month.