Unstable Mental Health. Please help me.

I am an Engineering graduate with an aggregate of 80%,  passed the degree in 2014. Later I prepared for several government jobs but couldn't get govt job due to external factors. From the last 2 years I have been trying to get a job related to my domain but due to career gap after graduation no employer is interested in offering job to me. I am not getting any support from my family to create self employment opportunity. My own family is against me, my mother is fed up of with me. Sometimes, I lock myself up in a room & cry endlessly. Every night is a nightmare for me due to the frequent bad dreams. My hair & beard turning grey, I lost charm in my face.I don't feel energetic. Sometimes, I feel suicide is the only option. Kindly please help me.