2000 Honda Accord transmission problems after a new mechani

I took my honda to a new mechanic to get a new battery and replace a motor mount. The car was runing great. He did the work and a final test drive. He said everthing was fixed and I paid him.

When I drove the car home it starting shifting roughly between 1st and 2nd gear when I quicly excellerated.

I took it back to the new mechanic the next day. He drove the car and said I needed a new transmission. He did not even look at my transmission fluid.

In addition, my cruise control quit workingl. Is it possible the mechanic somehow missed up my car? What do I need to do to fix the car. This seems like much more than a coincidence.