Unable to reset password of iPhone

my phone has been fine, in fact i haven't changed my phone passcode in the last year. but this morning my phone has been unlocked with that code for a year, but today it didn't unlock. I also have the latest apple watch, iphone 11 and macbook. but through these devices I get to a situation where I can't reset my phone's passcode. I have been using the apple brand for many years and am frustrated that they have ignored this issue for years. also because i can't buy icloud all the time i have to pay every month because of my phone asking me for another passcode without changing my phone passcode

[Re-Titled by Moderator]