Commiserations on your experience. You are not the first A320 pilot to be caught out in this situation.
As I see it, the autothrust system would have reduced power to compensate for increasing airspeed as you descended out of the tailwind .In consequence you commenced the flare with less thrust set than you had anticipated and the aircraft behaved differently from what you had expected. Because your attention would not have been focussed on the engine instruments coming into the flare you would not have been aware of the low thrust level.
One solution (as others have already suggested) would have been to commence the flare slightly earlier and to a slightly higher pitch attitude while still avoiding a last-second snatch overpitch . Probably this would have still given you an uncomfortable arrival, but not as rugged as the one you describe.
Low level tailwinds and consequent shear are often encountered unexpectedly, and therefore may not be planned for in one's mental model of how to fly the approach and landing. So one has to be ready to adopt a different model. In this particular situation an early reversion to manual thrust as soon as a tailwind is identified would be beneficial. This would ensure full pilot control over power settings immediately prior to and in the flare, which of course you do not have when autothrust is in use.