If you wish to reset your Swipe history (all your Swipes and Swipes by others on your profile that didn't result in a Match) see How to Reset my Swipes. This will allow you to see and be seen again on muzmatch.
If you wish to temporarily go offline and not be shown to anyone on muzmatch, including your existing Matches, go to
⚙ Menu → Settings → Deactivate.
When you log back in again, your profile will be reactivated, fully restoring your account.
To permanently delete your account, go to
⚙ Menu → Settings → Deactivate and enable the Delete account switch.