Tell me if you have had this problem with paperwork
I would suggest contacting the military archives in Saint Louis, as well as DA HQs for records, even if the unit lost records, there should be some within the system as all records to include medical records went full digital as of 2006, so there has to be some within the system somewhere, your medical records will be the headache as the request for them can take any where from a few months to a year or more. The good thing there is no time limitation for filing a VA claim.
Good luck.
I feel your pain, I have had my medical records lost 3 times during my career, luckily I learned from my DS during basic to make copies of every thing, so every time I was due to PCS and in the old days we hand carried all our records with us, I made copies of the entire record.