Car stopped accelerating and started shaking badly. Cut off while driving.

What is your question?

Was in motion when car stalled. Tried getting gas and it started just fine but it happened again. But the second time it didnt stall. It began to lose acceleration and started shaking real bad. I turned off and restarted it but it was still shaking badly and moving slowly.

What makes this problem better or worse?

Havent tried anything.

How long has your 1999 Buick Century had this problem?

Started out of nowhere