Sounds to me like you are getting too tense in your fingering arm. Let it fly a little looser, and relax. Put the attention into your fingertips where they hit the strings, let your arm find the comfortable spot, and keep your elbow loose. Bend your wrist a little more so you have a more direct shot at the fretboard. Find more comfortable positions that add speed to your changes. For example, like most, I'll barr with my index across the fretboard. But when a fast change comes up, I automatically barr a major with my index covering strings 1&2, while my thumb comes over the top of the neck to hit six, forming a very comfortable "squeeze". It may take a while to get used to something like that, but I've only been playing for 50 years... ;-)

Your guitar is like your lover. Learn to treat it like one. Expect to get back what you put into it.

p