Hesitation and Stalling on a 92 Mercedes 300se

Hesitation and stalling on a 1992 Mercedes 300se.
I own a 1992 Mercedes 300SE with 165K miles. Six months ago I noticed hesitation of three to five seconds at times before the car would accelerate. Other times it would not accelerate even when I would push the accelerator all the way down. On a 450 mile return trip earlier this week while driving 65 miles per hour the car started to de-accelerate and lost all engine power. I pulled to the side of the road, put the car in park. I turned the ignition off and restarted the car. I push the accelerator down a couple of times to test for power and it was restored. I then continued the return trip, this lost of power occurred three more times during the trip. On one last occurrence while the car was on cruise control. I noticed that the accelerator had gone all the way to the floor, which indicated that the car was trying to provide additional gas to the engine to maintain my cruise speed. The last time the engine cut off, I shifted to neutral, turned the key off, then back on, the car restarted, I put the shift into drive and continued on. Would welcome any ideas on the causes. Will not drive the car again because of safety concerns.