Thank you #citroen and #lindsayh for your comments!
Totally agree that II must have a bad form. I am a new user and though I have tried to follow very closely the techniques shown by Concept2 in their videos (supervised by my non-rower wife to confirm if I matched what was shown on the video), I have hit some practical difficulties (belly gets in the way) and some apprehensions: the biggest challenge has been to overcome the fear of grinding down my miniscus – I have had an ACL tear on right knee, when I was nearly the same weight, and lived with it for several months before I could get surgery done. During this time my gait changed because I wasn't confident in my right knee. As a result, my left knee took some toll as well. While researching whether rowing was right for me to lose weight, I came across articles suggesting that because of acute bending and flexing of the knee, there is risk involved in rowing at higher SPMs.
All of this led me to conclude that I might have to make some adjustments to make rowing work for me, one of which (my own conclusion) was that I would need to try something like 50/50 ratio for working out my lower and upper body during a stroke. I figured if I reduce SPM and increase DF, that would do it. So I have been rowing at setting 6-7 on my brand new rower, fully aware that I was probably working out my upper body more than I am supposed to, but with the rationale that this allows me to achieve higher drag factor during my workout (I made the mistake of not paying attention to actual DF number, I will target it to be around 120-130).
It appears I am maintaining a good HR. On diet, this month being Ramadan (muslim month of fasting) meant I had to automatically do better diet control than I have in the past attempts to kickstart my weight loss so the timing worked out well
Thank you for your generosity with your time and advice.