ABS Problems

Hello,
I have a 2000 BMW 528i with 132,000 miles. 6 cylinder. I think I am in big trouble with my car. My ABS light started coming on from time to time and would go out. This happened right after I had my brakes and pads replaced about 1 1/2 years ago. Two mechanics could not find anything wrong and said my brakes were still operable. Now about two weeks ago the ABS brake light will not go out.

When I first start up my car, I get all of the test lights, then all the lights go out as normal. I put my foot on the brake and put the car in gear and pull away okay. At this point I do not have any ABS lights coming on. When I attempt to make my first stop at a traffic light, etc. And apply the brakes, my brakes make a grinding sound and then the brake pedal pushes up towards me, and then I hear this clicking sound in the rear wheels. To make matters worse, the car starts to jerk and pulse and slow down in speed while my foot is on the accelerator. I would assume this is what locking brakes feel like.

I just know I am in for about three paychecks worth of work.