Parents against love marriage - threatening to kill themselves or lock me up

I am 24 years deeply in love with a guy from 3 years. My parents are against this because he's not frm our community. what should I do to make them understand?
I am trying hard to convince my parents for past 2 years. His family has welcomed me. My parents have started looking for guys to marry me off. They threaten me telling they will lock me up or kill themselves if I don't forget him and to quit my job because we are working in the same company.
I forcefully made my parents meet my boyfriend thinking that after meeting him dey would be OK but all our efforts went waste only thing dey tol him was we will never accept this u may be gud ,well off but v can't accept some one from another community into our family.please suggest

Since you both are working and you have been already trying to convince them from last two years. Here I think you should try a different approach. Now instead of trying to convince them, use emotional aspect . Do same way as they are doing with you, emotionally blackmail them , they are threatening to kill themselves , don't do it exactly rather declare that you agree to not to marry this guy because "your parents doesn't want it to be. But, you have condition, and that is, you will not marry ever because you can't live with someone else and will go in depression if you are married to someone else.

Here main things are :
1. You are agreeing to your parent's wish ie. not marrying that guy
2. But you are sacrificing your own life by not marrying anyone else ever.
3. You are declaring that if you get married to someone else, you will get depressed and will be not more than LIVING BODY but without soul.

Ofcourse you are not doing any of above in real, its just that your parents loves you, they just can't understand how much you r love is important to you hence, when you show them that you are sacrificing your life because of their will, they will eventually change their mind.

Hope you get my point.. but remember, its just my advice, its all upto you how delicately you execute it and its all upto you, please use your conscience before following any advice here or any where else.

Goodluck

Thanks for your advice :) I have also tried to emotionally black mail them but evn this dint work :( dey tol me it's better u do smthng to urself than spoiling the reputation of the family :-( My twin sister is also engaged to her boyfriend who belongs to our community. My parents are asking me to find some one from our community den dey r ready to accept..Even my sister doesn't support me and the only reason dey r telling me is he's not frm our community:(