Should you end it? A resounding yes!
How to end it? What's the problem really? You've tried to distance
yourself from her, but she may think that it's just a cold war and
will keep calling you to find out what's wrong. The silent
treatment is the wrong way to do it.
If you're too chicken to tell her face to face, the next time she
calls, answer and tell her the following:
" I want to break up with you now! I don't like you / this
relationship isn't working out / I want to see other people. I'm
not joking, please don't contact me. Bye. "
Very simple, right?