I cant tighten the nut on my track rod end, the whole thing is just spinning.

Does this mean the track rod end is worn and needs replaced?

No almost certainly not, it probably just means that the taper hasn't bedded fully into the socket yet. You need to use a large pair of grips to force and hold the joint together whilst you do the nut up tight enough to hold it in and then once it grips up you should be able to tighten it properly.

I'll give this a try, got to tellyou though that this car repair thing's fighting me every step of the way

Easier way put a jack under the joint to put weight on it. Works every time.
Adam