Hi
You have to bear in mind here you have two things going on at the same time: quitting smoking and starting vaping. While vaping can and does get nicotine into your system, your body has to get used to not taking in all that other crap it used to get from smoking. That's the quit smoking withdrawal part. In other words, this isn't just about the nicotine.
As far as cravings go... yeah, it's been said already - everyone is different about how hard this is. One of the things you need to figure out is what is your right nicotine level or levels to deal with cravings. It's a very individual matter. You can take two people with the same 2 PAD smoking profile and at 24 mg nic one person will get bowled over and can barely tolerate 12 mg's. While the other person is barely holding it together with 24 mg and needs something even higher. If cravings really seem to be a problem you may want to pick up the next higher nic level and see if that works better for you. One of the best things about quitting and switching to e-cigs is the flexibility. Every person gets to customize the nic level to their own needs.
It does get better. Cravings will go from multiple times a day, to daily, every other day, every few days, weekly, a couple times a month etc. as you go along. The frequency and intensity of the cravings falls apart over time.
One of the harder things for new vapers to figure out is you have to vape enough. Vaping is not smoking. You don't get an instant rush or buzz from vaping as you do from a cigarette. And a PV doesn't do a thing for you unless you pick it up and push a button every time. There is no smoldering cigarette sitting there, reminding you to finish it. It's just not the same thing so you actually have to work at vaping enough when you are new to it until it becomes second nature.
All I can tell you is no matter how "rough" those first couple weeks might have been for me, this time it was a lot easier to quit than any other time around. And over two years later I'm still quit. This actually can work. Best wishes sorting it all out.