I found alot of topics with the same problem but they always lost their password. I have the password still in my KeyPass but I have lost my keystorefile. Is it possible to restore it with help of the password or anything else? Google Play doesn't let me update my app :/
Unfortunately, there is nothing you can do to update the app once you lose the keystore file. Your next best option is to just release the update as a new app and inform as many of your users as you can.