Interesting. Your current workouts are Long Slow Distance aka "LSD" workouts. These are great workouts for basic fitness and they will make you faster. Additionally, this is the base workout for elite rower.
Since you set a goal of 10^6 m between Jan 1 and Mar 31, keep on it. But let me make a few suggestions:
1. Get a Heart Rate Monitor.
2. Add a 5 min. warmup. I like to start with rowing with feet out of the stretchers (which teaches balance and a good finish) and doing the "pick drill" (which teaches a coordinated stroke and a good catch). The pick drill is starting at the finish and (i) take 20 strokes arms only, followed by (ii) 20 strokes arms and body swing, (iii) then 20 strokes arms, body and 1/4 slide (about six inches), (iv) next 20 strokes arms, body and 1/2 slide (about 12 inches), and finish off with rowing 20 strokes at full slide. For a LSD workout ,I usually take 1 or 2 semi-hard 10 stroke piece (about 2:00 pace). The purpose is to get your heart rate up to roughly 50% of the way from resting pulse to maximum heart rate, and to also have your big rowing muscles ready to go. I then stop rowing, strap myself and start my workout. Here is a demo of the pick drill ( https://www.youtube.com/watch?v=aoQkcuWOtAw
3. As others have opined, add some variety. Feel free to take a short breaks every 15 - 20 minutes to drink some water, or change the TV channel, or find a new podcast, or whatever. I will sometimes set the drag at 10 -- makes you strong, or down to 2 -- makes you quick, or some place in between. I will also vary the wattage. As an example, 20 min @ 160W (2:09pace), have a drink and then 20 min @180W (2:05 pace), have a drink then 15 min @160W.
After March 31:
A. Once a week add some short High Intensity Interval Training aka "HIIT". This is to build your anaerobic (without oxygen) system and to prime your peak aerobic (with oxygen) system. My favorite (or most dreaded) is 10x1:00/1:00r (10x one minute on with one minute rest). Some alternatives are: 8x500/1:30r, 10x250m/1:00r, 10x1:00/0:30r. Make sure you get a good long warmup first (or row the first two intervals at a slower pace). You want to make sure you row these pieces in control and well and preferably with a slight negative split. Week 1, try them at a 2:00 pace, Week 2, a 1:55 pace, after that drop the pace by 1 - 2 seconds each week until you reach your plateau. After your set, give yourself a nice long 15-20min warmdown. Your pace for the 10x1:00/1:00r will by +/- 2s/500m your pace for 1000m and it will be 5 seconds (+/-2/sec) faster than your 2000m time.
B. Once a week some longer intervals or single distance pieces. These intervals should be done between 90% to 100% of all out effort. Suggestions all-out pieces 1k, 1.5k, 2k, 3k, 4k, 5k, 6k or 30 mins; Suggestions for long intervals, 3x1500m/3:00r, 4x1000/2:00r, 3x2000/3:00r, 2x10:00/3:30r, 3x5:00/2:00r, 3:7:00/3:00r. For all of theses piece, get a good warmup and warmdown.
C. Fill in everything else with LSDs.
On the various types of training ref: http://www.row2k.com/features/1035/Stay ... ear-Round/