Transmission shudder advice

So I got the infamous shudder and quickly panicked and took it for a wheel balance hoping for the best.. still a shudder so I take it for a transmission fluid change shop calls and they tell me bad internal transmission so then I start really freaking out until I read more into it.. so I’m thinking to just go for a transmission flush and hope that solves it all. What would you guys recommend?

p.s I just hit 223k miles