Wow that sucks, sorry to hear.
As far as welding a drive shaft to a coil over?! That crazy. They are two separate components that do different jobs. Sounds like you may have been hoppping the front end up and down (hence braking the coilover) and when you made contact with mother earth, your driveline was still spinning and one end, probably on the differential side was stripped out of the toothed gear ring inside the Diff. Or inside one of the CV joints, since those are also geared and held in by snap rings.
If the diff isnst the issue and its just a CV joint, then you're good to go, since new CVs and axles are not to much, but you are Titan Swapped so the cost could be a bit higher. Let me know if you need any help and I'll make some movements in my schedule to come help.
(Do me a favor and punch that welder in the forehead for me! Weld a coilover to Drive Axle, haha Lol)