runaroundtime

broncovet, thank you for the advice and information.  I got the info on my decision today by speaking with my VSO (who isn't too helpful).  I was denied service connection for my TBI.  The VA's reasoning for this is that my service records and separation physical (fall 2008) were silent for TBI.  TBI wasn't something there was a lot of awareness on when I was in, so i was naive to my injuries for several years.  I spent 6 years in the infantry from 2002-2008 with 3 combat deployments, I have been exposed to IED blasts (twice within 25 ft), RPG blast within10 ft, and a vehicle rollover in which i was knocked unconscious.  There are service records for my MVA, but they do not discuss TBI as it was from a battalion aide station and TBI wasn't really a thing then.  
Within weeks of separation I did an initial physical with the VA for my medical coverage and screened positive for TBI and was scheduled for a neuropsych exam in 2009.  Long story short, I struggled with my transition for a few years, and blew off all VA appointments/disability claimes when I first got out.  I got my act together and eventually filed for disability with VA in 2017 and was service connected at 70%, but denied service connection for TBI at that time as well.  
During my initial appointment with my VA primary care Doc, I again screened positive for TBI and began treatment with the VA polytrauma team.  I took my care more seriously this time around and have been very proactive with my treatment.  I have had an MRI that detected a bleed in my brain and also did the neuropsych exam which I mentioned already.  
In 2019, I submitted the supplemental claim for TBI that was just denied.  With this I submitted all my VA records, and a lay statement from the person I was sitting next to during the rollover, where we both lost consciousness.  My TBI C&P exam was done in April of 2021 and the DR listed the TBI as service connected.  
In the decision letter the VA relied on the lack of TBI diagnosis in service and not being mentioned during my separation exam, even though i screened positive a few weeks later with the VA polytrauma team.
I would appreciate any advice on how to best proceed.