How to get your apps and passwords back after pressing the merge button to iCloud

So when I was logging out of my new temporary iCloud account to log back into my old one bc I forgot the password I saw this merge or don’t merge button I pressed merge thinking it wasn’t going to do nothing and I saw all the apps I had on the temporary new iCloud were on there I was so confused like where we’re all the old apps with this iCloud account and when I went into my settings none of my old passwords were there to just the new ones from the temporary account can some tell me how can I get my apps and old passwords back pls!! I need help