I agree with the general thrust of the responses so far - go around - pile the power on while pitching level (assuming you are flaring) while rolling the wings level and getting on the rudder.
Whatever happens continuing the landing is probably not a good idea - you will have had going around drilled in to you and it should be familiar - in this case you found yourself somewhere unfamiliar, transitioning to a familiar situation (the go around) will have let you settle your nerves.
After such an event you will have been in unfamiliar territory, your nascent muscle memory would have been negated and the result was the heavy landing - another day maybe a dinged prop, collapsed nose wheel or a u/c leg punched up through the wing.
All that said - possibly initiating was not as bad as you thought or I would have thought your instructor would have taken over; if the landing was really hard I would have expected the instruction to have taken over and not continued the subsequent taken off and then inspected the u/c; finally, if it was so bad that you should have gone around I would have expected your instructor to have has you so at least one go around that he would have initiated without warning on one of your subsequent approaches.
Things are sometimes not so bad as we think.
Last edited by Ebbie 2003; 31st Aug 2013 at 00:51.