Hi, Max Trinh
I’m sorry this happened. Since you bought Minecraft on your new Microsoft account, you can focus on signing the launcher into that account. In the screenshot, the sign-in window is asking to verify an email address. If the address shown isn’t yours, don’t enter a code or try to use it.
Close that window. In the Minecraft Launcher, select the account menu in the top-left corner, choose Log out, then select Microsoft Login and Sign in with a different account. Enter the new account that bought Minecraft.
If the old account keeps appearing, check Windows Settings > Accounts > Email & accounts and remove the old account from the device if it’s listed. Then reopen the launcher and try the new account again. Removing it from Windows is different from recovering or closing the account itself.