I have an asset in a self directed IRA that is now worthless. How can I remove it from my total value of all Traditional IRA's?

Your IRA year end statement form the financial institution should reflect the year end value of that IRA account.

Investments in self-directed IRAs becoming worthless seems to be a relatively common occurrence.  The IRA custodian will continue to report the original value until they accept an independent appraisal of the asset to change that value.