Separating Upper Control Arm from Spindle - Nut Spins!

[AlexHart]

Hi,

I tried changing my lower ball joints (1984 300CD 123 chassis) earlier this morning. I took everything off and the last thing I needed to undo was the spindle from the upper control arm ball joint. The nut that holds the spindle to the upper control arm joint was extremely tight. After pouring blaster all over it, I gave it way too much pressure and broke something (I think). Now, the nut spins with the bolt. When I turn the nut, it spins the entire ball joint. Does this mean that my ball joint is busted? What did I do wrong? Huge failure. Not sure how I can take the nut off now to remove the spindle from the upper joint. Has anyone had trouble with this bolt? Is there any way to fix it now?

Any help would be truly appreciated. I'm speechless. I was so close. Thank you.