visualware

My 2001 CLK320 hesitates upon acceleration. This is an intermittent problem that seems to be getting worse over time. It also occurs in the morning after the car has been sitting overnight. It feels as if the car loses all power and then regains it suddenly. This is becoming a danger on the road to say the least. Yesterday the car stalled at an intersection. I was able to restart it and pulled to the side of the road and let the engine idle for about ten minutes. I continued on to work without a problem (45 miles) and returned home that evening with no similar issues. HELP!!