multiple errors while trying to add & edit content type

I'm getting multiple errors while trying to add & edit content type.
For example I just went to Structure to add a new content type. I named it Article 2 and when I saved it:

PDOException: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'i_health3.cache_views' doesn't exist: TRUNCATE {cache_views} ; Array ( ) in cache_clear_all() (line 169 of /Users/user/Desktop/i_health3/includes/cache.inc).

Then when I go in to manage the fields, it lets me edit fields but when I saved it, I got this:

Notice: Undefined index: article_2 in _field_ui_bundle_admin_path() (line 309 of /Users/user/Desktop/i_health3/modules/field_ui/field_ui.module).

Then when I close it & re-open it doesn't have the error, so I edit the fields & saved it & got this error:

Add new field: the field name field_tags already exists.

Then when I go back to it, nothing was saved!
What is going on?