My heart goes out to you. This certainly is not what you were counting on.....but don't give up! Just like you said. Don't throw in the towel yet. I love what the others have said, and Fiona is right - it's so easy for us to focus in on the stimulation rather than experiment around and concentrate on whether you are noticing a reduction in your pain.
I'm sorry that your thighs end up hurting. I wonder what on earth that could be from?
I really like the way Fiona said to turn it off completely and then start out real slow, and experiment with the pulse width and amplitude. I know you've already been doing this and you're getting frustrated, but please try to hang in there. Some people have to go to several tweak sessions, so it's not unusual that you've been 3 times.

You're in my thoughts
and Prayers,
Rae