Wow Mike, that is an incredible story! When a doctor tells someone "to smoke" and then you get better from smoking. Wow.
Sounds like you are almost in perpetual motion! I also now understand the cost factors that you are dealing with.
Well, it would be great if you can sit yourself down and start making some of your own PV's with all the parts you have but it sounds like that might not happen anytime soon. So May I suggest that you get yourself a more heavy duty PV so that at least you can cut your tobacco habit down a bit?
But first of all, may I suggest that you vape at a higher voltage then 3.7. I think you would be better off at 6 volts using a high voltage 510 atomizer. The 510 burns the hottest and at 6v is optimum in vaporizing the liquid in your cart thereby giving you the optimum in nicotine dispersal.
I would go with either a Silver bullet or a Chuck, both of these units are pretty heavy duty and would stand a better chance to last you longer then a conventional e-cig. But please be sure while vaping at 6v to use only "PROTECTED batteries" in these devises and only use a High voltage atomizer made to vape at 6volts.
Do you think that this plan might work for you?
I do use the LR attys most of the time, they are supposed to vape at 5 volt. Not yet tried a dedicated 6 volt system but it could be the way to go.