I honestly believe that you're over thinking this. After seeing a bunch of good landings and having a bad one under a slightly different scenario, it would be very easy to look at the scenario and blame that. Throw in your embarrassment and it would be even easier.

So you had a bad landing. It happens. Its unfortunate that it happened with passengers, but even airline pilots bounce one in every once in a while. You're not flying a jet that is much more weight sensitive, its just a small plane. Just relax and do better next time. The more you think about how to do stuff differently under minimally different circumstances, the more you're going to screw up a technique that you seem to have down quite well.

I'd say just keep on keepin on. If the next couple times you go up with a heavy load the same bad landing happens, then maybe its a systematic problem, but don't go changing everything just because of one bad landing.