Disability Benefits: How to Apply for SSDI Before You Have a Definitive Diagnosis

I have been incredibly ill for 2 years now. I have been to a few doctors without a diagnoses or incorrect diagnoses that was later ruled out. I am finally getting test results back that point to an auto immune disease. We also have discovered cardic issues and a few other health problems that arent typical of a 28 year old. My condition has deteriorated rapidly in the last 6 months. My doctor officially told me I can no longer work or drive and that I needed to file long term disability. We have many tests to do still. But we haven't found my diagnoses yet. Should I attempt to file for ssdi with severe limitations but not knowing exactly what the diagnoses is yet? I have been diagnised with a couple illnesses that others have been approved on ssdi due to meeting FRC. The "main" illness destroying my life is still unkown though. I fear my family is heading into financial despare because I can no longer provide my income, but also don't want to delay my ssdi case if waiting for the right diagnoses would speed it up. I am in Wyoming. Thank you for any insight.

Disability Benefits: How to Apply for SSDI Before You Have a Definitive Diagnosis