I'm a 23/5'9 (god, I dont even know how to write this feet, inch stuff)/70kg(I finally gave up

Now there is an indoor rowing competition coming up on the 19th of january.
As for my training, I'm quite unspecific now, mainly trying to improve my technique, as I didn't do that many sessions on the C2. I can hold a 2:15 pace for one hour very easily while talking to my teammates and if I try really hard a 1:46 pace for 500m. I do about 3 - 4 sessions a week on the erg, one on the water, one in the gym, because my philosophy is to increase frequency slowly rather than to have backache which is my problem sometimes.
My question is: Is 7:30 a realistic expectation for the 19th? Should I be more specific than just doing two longer pieces, one interval session and a 3x4km (or something similar)? Or will progress at this point come naturally as I started rowing only a couple of months ago?
Thaaaaanks,
wittgenstein (I misspelled my name, I know
