Depression because of relationship.

I HV been going through deep depression from last 2 weeks. I can't stop myself thinking.i have changed my environment i went on vacation to rishikesh stayed in ashram with family to gain peace but nothing worked.still thinking....I found myself a looser...I again n again thought of dieing ..Nothing left in my life...In the beginning i get into a relationship with a guy i didn't know much about him he is aggressive,short,tempered,impulsive.He used to tell everything in the beginning but now he stop sharing things with me ..He is hiding his phone n in return blame me that i always doubts him..i got addicted to him i thought and even tried 4-5 times of leaving him but i got fail. He starts shouting on me and even he stop making calls. I used to call him all day. I think he get irritated with me. I have my exam after 3 months which decides my career but when i study i start thinking about him. What should i do please let me know