I'm designing a database for contacts and I'm looking for some feedback on the current design.

What i want:

• A contact can be a person or an organization.
• A contact can have many groups.
• A contact can have many emails and addresses
• A contact can have one organization (employed)
• A organization can have many contacts (employees)
• A group can have many contacts.

What i have:

• Contact(Id, PersonId (FK), OrganizationId (FK), EmployerId (FK, self reference))
• Person(Id, FirstName, LastName, Birthday)
• Organization(Id, Name, Founded)
• Group(Id, Name)
• ContactGroup(Id, ContactId (FK), GroupId (FK))
• Email(Id, ContactId (FK), Name)
• Address(Id, ContactId (FK), Street, City, ZipCode, Country)

What bothers me the most is that the contact entity has one organization or one person, and also a self reference (EmployerId) if a organization has employees (which are also contact entities) and vice versa.

Is this a problem or see you a better way?