I completely understand what you’re going through and at the same time I also understand what your parents are feeling. In this day and age when cases of molestation and all kinds of atrocities on girls are prevalent, its natural for parents to try and shield their daughters from any harm. But, at the same time, you’re not supposed to live your life locked up in the house forever. And I’m impressed by the fact that you’ve been respecting their wishes and not rebelling. Kudos to you!
You say you’ve calmly tried to explain your position to them but you end up being emotionally blackmailed. How about you try something we call the “worst case scenario technique”? Sit down with them and ask them what’s the worst thing they are afraid of, that would happen if you had a little freedom. Once they share their thoughts, try and brainstorm with them about the possible safeguards against their fear like a phone call every hour to let them know you’re safe, or maybe an app like Google Latitude that lets them see where you are at any moment, contact numbers of the friends you’re going out with etc. Once they see that there are lot of ways they can let you have your fun and freedom and still keep a watch on you, they might relent after a while. Give it a shot and let us know what happens! We’ll be waiting eagerly to hear from you!