iTunes account

I don't know what this means.

Damage control wrote:

... deleted previous iTunes iPhone account

It may mean:

• You logged out of your iTunes account in iTunes on your computer. In that case, simply log back in under "Account" in iTunes' menu.
• You had been backing up an old iPhone to iTunes on your computer, and you deleted this backup. In that case, unless you can retrieve this backup from your computer's backup, you would lose the backup's contents. But you could still retrieve your apps and whatever music you have on iTunes.

If you backed up using Time Machine:

Use Time Machine to back up or restore your Mac - Apple Support

If you backed up some other way, you would have to figure out how to restore that backup.