I have to agree with the previous posters. If you were temporarily out of control, your first reaction should be to push the nose down and go to full power, effectively initiating a go-around. If you then exit the turbulent area without too much energy (speed & height) you can reduce power and attempt the landing again, but if there's any doubt at all, go around.
The fact that you had trouble maintaining height and speed suggests you were awfully close to a stall, which is quite often fatal at that altitude.
On you second attempt, carry a little extra speed. Half the gust factor is a generic suggestion, but talk things over with an instructor to look for specific advice.
BTW random turbulence should not, on average, cause you to lose any significant speed. Sure, you might have trouble controlling the bank but if you don't start pulling on the stick/yoke, you should not lose any significant speed in random turbulence - although your airspeed needle will fluctuate a lot. Your story either suggests that you pulled your nose up as a (wrong) instinctive reaction without adding power, or suggests windshear (-sheer?) on final. The latter would be cause for a pilot report to the tower/FISO/AG operator so that others can carry a little extra speed on final too.
So definitely talk it over with your instructor and get his opinion on this!