After a minor rear-end accident, slow acceleration and the brakes are not working properly?

It sounds like the impact has stopped the regenerative braking somehow, we need to run a CAN scan to see what's going on.
You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is a CAN scanner on Amazon for about $59.00 if you need it. They have cheaper and more professional units as well; this one is the middle of the road.

https://amzn.to/3tbyO8F

Please go over these guides and get back to us.