Slow to accelerate and not shifting properly

Welcome to 2CarPros.

The first thing I would recommend is to scan the computer for diagnostic trouble codes. If the check engine light is on, there will be codes.

Here is a quick video showing how it is done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner. However, most parts stores will do it for you or lend / rent a scanner. It needs done.

As far as the symptoms, when there is a power loss as you described, there could be many caused, but my first suspect is a plugged catalytic converter. Take a look through this link and see if anything mirrors what you are experiencing.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Let me know. Also, let me know if you have other questions as well as what codes are found. The codes will help me point you in the right direction.

Take care,
Joe