You're sending infinitely increasing data. Maybe it's because "while True"
think of a way to reformat this
msg = bytes(f"{len(msg):<{HEADERSIZE}}", 'utf-8')+msg
while True:
r = mouse.position
print(r)
t = mouse.press
#print(r, t)
msg = pickle.dumps(r)
as I see these two highlighted lines are handling sending the mouse position. They should stay intact, but you can think of a way to move other lines outside the while loop