When the action on a guitar is sky-high, it's very likely in need of a neck reset. We say the neck is shooting low. Sometimes other solutions have been employed to bandaid the situation - shortening the saddle, shaving the bridge down. It would be important to reverse these interventions as well. Often a refret, a new saddle and nut are also required, and that's what makes these the big job!
guitar's action is sky-high, and a setup doesn't fix it
guitar feels extremely challenging to play (fretting hand fatigue)
saddle is low but action is high
bridge is suspiciously skinny
neck is shooting low
Guelph Guitar Repair is your home for neck resets