Becoming discouraged

I've been reading everyday what my fellow VET brothers and sisters have been posting on here and in relation to filing a claim for benefits/compensation I'm becoming discouraged. I just Filed a claim about a month ago. I was honorably discharged ( 1991)with a clean medical record and have not really experienced any issues until about the Last 10 yrs maybe more with the exception of PTSD ANXIETY trouble sleeping in relation to an accident that occurred on my ship. I've been told by the VA yrs ago that I don't have any service connected disability and therefore not entitled to any compensation. Just wondering, can that be challenged or disputed? I have no medical record of those issues, I have always just delt with it. Is there any hope?