Difficulties Caused by Attaching Menu Link to mosimage - Joomla! Forum - community, help and support

i creating first site joomla , have run problem can't seem correct. i'm not technical, nor have worked on web sites previously.

i editing category in content several images had inserted using mosimage. attached menu link 1 of images, (totally forgetting highlight , click on 'link' button above text area.

so highlighted code {mosimage}, in 'link menu' area linked main menu, stipulated menu item wanted link to. somehow crashed joomla. when went site, menu item has appeared @ bottom of main menu. isn't had intended happen, remove item main menu.

when click on item in main menu, error message saying, 'you not authorised see resource. please log in'. don't have log in area on our website confusing. menu item had hoped link working showing correct content.

i can not find anyway remove item main menu. isn't listed in main menu or of other menus have on site.

sorry long winded explanation, thought should explain how got predicament. can please help.