Well, I work at home in front of my computer most of the time. Only go to the office for meetings and to drop off/pick up work. When I started with my 901 (wow, has it really been almost a month now?), I was chain-vaping my 18mg non-stop all day and all night.
So when I placed my order with V4L, I upped it to 24mg. It's made all the difference. Of course, the 1st day I vaped all day because I had so many new flavors to try. But today I vaped more like the way I used to smoke, so the 24mg is working out better for me. I was a 2-pack a day smoker of Misty Lites, sometimes Virginia Slims.
Based on your description, I'd get the 24mg with maybe a few 36mg to get you over the rough spots. You can always come down later.