I am in deperate need of help as this thing is making me depressd

Hello, I am a Govt official, My brother has some issues with my uncle regarding marraige problem and now it threatens my job and prestige. Actually 15 months back my uncle's son proposed my niece for marraige. But he later refused. There were some tensions but it became normal. Two months back when my niece was all set to be engaged to another guy. My uncle and interrupted and created a lot of ruckus and said that it was his RISHTA and that he wont let anyone marry her and asked for my niece's hand for his son. This all ruckus led to the cancellation of engagement from the other side(where she was set to engage). And few weeks back the son of my uncle refused again and this led to a lot disturbances. Now my brother is threatning to my uncle and his son. My brother has no link on contact with me for about a month since the cancellation of engagement. Now my uncle is threatning to lodge a complaint against me for intimidation as i am a govt official. ( even when he knows my brother has very little association with meand doesnt listen to me). I have kept my distance from both my uncle and brother and have no contact with both of these for a month and am posted in a different city right now. What can i do to protect myself from this and can i do anything that can help me avoid all these( as this can effect my future promotions and postings). Should i give any sort of affidavit or any do other legal thing.