MST isn’t that PTDS?

I filed a MST case with my Comp case. They denied it but tell me I have a adjustment disorder, they gave me 50 percent service connected. But change it to 30 and then say it’s not PTSD? He blame me for his troubles and then committed suicide. Now I’m be harassed by his family. It took 8 years to finally settle my case only to be slap in the face again. What can I do?