ASR [Automatic Speed Reduction] light will activate and car can go into "limp home mode" for a variety of reasons.
As simple as the floor mat jammed under the gas pedal, to malfunctioning acceleration linkage, switch(s), wiring harness and / or actuator.

You can either take it to a mechanic who has a MB computer diagnostic system or if you're a DIYer, you can build Arthur Dalton's code reader and post the codes. The list members will help you when we know the codes.

Been there, done the DIY with the help of the forum members.

PS Take care of it now, because it will keep recurring.