Did you loosen the pinch bolt under the rear right of the swing arm(under the axle) prior to attempting to remover the axle?
I’ve never heard of anyone having an axle break in half while trying to remove it.
Can you post any pictures or give us any other info?
Like how much of the axle actually came out?
You might have to use a hacksaw or something similar to cut the axle. This should help you get the wheel out of the way, then you could very carefully use a hammer and punch/chisel to get the remaining portion of the axle to thread out of the swing arm.
Without seeing what you’re dealing with that’s the only idea I have for now.
Good luck