B737 NG Captain reported control input responses were sluggish then they received a stall warning while over the runway resulting in an abrupt landing.

Narrative

This morning we were inbound to ZZZ on flight XXX. Weather in ZZZ was reporting 700 broken and winds were out of [the] southeast at around 8 kts. Our landing weight was approximately 152.5 and we were on the ILS [Runway] XXR with flaps 30 selected. We had pulled the weather prior to [the] start of our descent briefing and with the rain at the airport we pulled wet landing data from the ACARS system. Our REF speed was approximately 147 kts. and with the winds light there was no additive. We selected AutoBrake3 with the heavy weight and wet runway conditions and an exit at; or after [Taxiway] XX was briefed. At approximately 600ft. the runway was in sight. I declared landing and disconnected the AP/AT for landing. The aircraft felt very heavy and the controls seemed sluggish in response to input. I recall having added N1 to approximately 65 which I felt unusual at the time. As landing was being made and during the flare the stall warning went off and the aircraft seemed to fall the last 10 feet resulting in an abrupt; but not hard; landing. The aircraft did not encounter a tail strike and a normal rollout and exit at [Taxiway] XX was accomplished. Upon taxi in FO and I discussed why the horn had gone off. REF speed was a few knots above the 5 kt. add and with the wind being reported as southwesterly we ruled out a possible wind shift to a tailwind. The only conclusion I could draw out if this was that the aircraft stalled; if that's what actually happened; due to inaccurate cargo/passenger weights and the subsequent lower airspeeds resulted in a potentially dangerous situation. Pull FOQA data on the aircraft and see what actually happened compared to what I interpret happened. I also need to remember that an aircraft can stall at any time and in any configuration even if you are doing everything right. Go-around when that voice inside my head says something isn't right.