No forcing
post up a few pictures if you can and we can help you figure your next move. If you can't post any, can you email or text? I'll help.you post them so you can get some more eyes looking at it.
It sounds like you got the nut off and the ball joint removed, but now you can't thread the nut back on at all? (Should be able to thread a few turns before hitting the locking end). It might be the nut that got damaged if you pressed on it with the ball joint tool...
Try it with another nut to see.
If you had this much trouble just with the toe arm ball joint, I would strongly consider when doing the LCA you remove the bolt at the other end to gain your movement instead of the ball joint end. The lca ball joint end, for me, was much harder than the toe end
