If you use the console command "reformprogress" followed by a number you can change yourself to a monarchy or a republic then get yourself enough points to get back to the tier you get parliament

When that happened to me I downloaded cheat engine to temporarily remove the console block in ironman and just complete the mission without actually adopting the reform.

Just devastated.

And its a Parliament, so no Imperial Diet. F.

Time to roll back the saves

Assembly of the Holds isn't available to my Magocracy Amldihr, and i will never recover