The problems description is somewhat limited but I might suspect something is up with the clutch. Throw out bearing sticking or slow to totally release or whatever. To experience a severe effect like even minor delayed whiplash is unusual.

That much wear present in the other components and they would have already failed I suspect. Or very obvious. I guess there may be a chance your center splines on the driveshaft are toast is perhaps another possibility. Allowing almost a full turn before locking. This would also be unusual.

Last thought is the bell housing bolted down well or loose?