91 Honda Accord- Blinking S

I recently purchased a 91 Honda Accord- automatic, 103,000 miles. It’s a little slow to “kick into gear”- like when I’m driving around my neighborhood at very low speeds, it feels like it’s revving too high- like it’s not in the right gear(hope this makes sense). And after driving approx. 60 miles on the highway, the “S” light started to blink. I know that the car had a problem a couple of years ago- it got stuck in “S” mode. But that was fixed. And the light, the “S,” wasn’t blinking, as it is now. Could this be a cheap fix- maybe a burnt-out TCM (I read that on another car site) or does it signal a larger problem? Thanks.