Based on advice given to Noobs in the Info pages I ordered (a lot!) of 24mg e-liquid, and I had a similar first couple of days. Finally I realized the shaky and sick feeling was nicotine OD from the 24mg. I think it would be better if they recommended buying a variety of mg levels and start low.
I also had serious lung pain after vaping, which I think was PG reaction. I read about Virgin Vapor here at ECF and they sell VG only e-liquids, no PG unless you request it added. They also recommended starting with 12mg and go up only if you need to. I only do VG now and no lung or throat pain since.
Currently I mix my e-liquids, a few drops of 12mg and a drop or two of 24mg. I guess I am making 18mg? Still trying to find just the right experience. Maybe I should just be okay with wanting to spend more time vaping than I did smoking and do the 12mg?
I use a Riva 510 and just ordered a Riva UNC which has a bigger battery, I hope that will push the 12mg a little better.
The whole PV thing is waaay more complicated than analogs but after just a few weeks my lungs are happier and I can actually smell stuff now. I am very thankful for the ECF Forum otherwise I would never have gotten this far!