Dear friend, try to see the movie in YouTube called 'The fiddler on the roof', where all the daughters break the traditions to pursue their love, you might like it, as the story is very much like yours.
Traditions ,caste ,etc are almost impossible to change ,however it is sometimes possible to relent, bend and give some allowances ,depending on the priorities and values that people uphold. In your case, your life, happiness, love ,freedom of expression ,emotional health are possibly the priorities that are to be given topmost attention. But there are few who still believe in the traditions and belief that money and prosperity is all ,emotions and feelings are worthless commodities and waste of investment. Try to be assertive ,dont go on a confrontation or collision course, but politely and respectfully ,discuss with your parents presenting only the positive points that are in tune with their expectations ,like financial prosperity, your plans ,happiness ,assure them how happy you will be. You can try to appeal to their emotions and get them there , try telling them what it means to you ,how you will suffer all your life letting your true love go, how the world is moving, changing ,emerging ,and renewing. Share with them how it is affecting you presently and assure them of success and happiness. Do what you think is the best while keeping your calm and patience ,and persevere relentlessly. Dont get discouraged ,keep at it ,someday the cracks will appear. All the best, we can only try and hope.