Okay, first things first: go get a glass of water for that headache and drink it while you read this. If you can manage it, have two. I'm sure I'll type enough to last you.
The headache/sweating/shaking does sound like it could be too much nicotine, rather than too little. However, if you've tried to quit before and know what your personal nicotine-withdrawal symptoms are, that's more significant that any "most people" advice we can give you. Of course, you might be experiencing both at the same time -- too much nicotine, plus a craving for something else that you've been trying to satisfy with nicotine instead. That seems likeliest to me.
There are a lot of addictive substances in tobacco smoke other than nicotine, and different brands contain different addictive substances, so your "nicotine withdrawals" might actually be withdrawals from something
else in tobacco smoke that vaping more nicotine won't satisfy.
You know how people say chocolate is addictive? There's a substance in chocolate called theobromine, similar to caffeine but a weaker stimulant. It's what makes people say chocolate is addictive, and also contributes to chocolate's reputation as an aphrodisiac.
I know Marlboro Reds have theobromine in them; I'm not sure whether their other flavors do. But it might be that a square of dark chocolate would help take the edge off your cravings. (Ah, to have the disease that needs
that cure!) If you don't like chocolate, you could try tea or a cola; they have a little theobromine in them, too.
If that doesn't help, there are several things you can try. Some people just keep having a few cigarettes a day to taper off their other addictions while they retrain their nicotine addiction to attach itself to vaping instead of smoking. Some people use snus or another smokeless tobacco, to avoid smoking and still get the full panoply of addictive stuff in tobacco.
In my opinion and experience, which is to say that this is neither tentatively stated nor objectively factual, most people do better with a gentle approach to quitting smoking and more emphasis on enjoying vaping. I know a couple of people who took the grim-determination approach, treating vaping like patches or gum and turning it almost into a punishment to themselves for craving cigarettes, and they both still smoke. (A third person, who used to take that approach once a year or so and go back to smoking in a week, one day discovered an ecig he just enjoyed the daylights out of, changed attitudes, and quit smoking that weekend.) I have a lot of anecdotal evidence to suggest that a playful attitude of enjoyment toward vaping will improve your chances of success in quitting over a determined/desperate-to-quit strictness. The plural of anecdote isn't "data", but at some point, it does become "statistics".
Above all, don't panic, and don't quit vaping. There's a lot of good information here in the new members forum and in the
infozone on what to expect while you switch. I quit smoking "accidentally" and effortlessly, blowing right past the nicotine cravings, while trying a kit I was going to give a friend, but weeks later, I was still getting bizarre symptoms -- acne like I've never had before, new kinds of headache, mood swings, insomnia, lethargy, and all kinds of weirdness; part of it was withdrawal from the
other stuff in tobacco, part of it was over- or under-dosing myself as I tried to figure out how vaping differs from smoking, part of it was underestimating how dehydrating vaping can be, and part of it was my skin and other organs getting rid of the accumulated crud I'd been taking in with the tobacco smoke.
Some people are sensitive to propylene glycol (PG), used as the base liquid in a lot of ecig juices. The infozone has more about what that sensitivity feels like; it doesn't sound like what's going on with you, but it's worth a look. You can get vegetable-glycerine-based (VG) liquids instead to see if those agree with you better.
Your own brain will teach you how to vape, because it wants that nicotine; it's taking secret notes on everything that works and everything that doesn't. It wants you to give it nicotine as efficiently as possible. But that's still a trial-and-error based approach; you have to do something once for your brain to figure out how efficient or inefficient it is. You have to consciously come up with the ideas to try for your brain to evaluate them.
I'm afraid this also means you're going to have to play. I know, it's worse than the chocolate thing!
Blow vapor rings. Try French inhaling and exhaling. Try pulling the vapor into your mouth and holding it there before inhaling. Eventually, you'll find yourself settling into the pattern that works best for you.
If you find that you're spending a lot of time chain-vaping to address your cravings, get up and move around. If you have the eGo passthrough that you can unplug and carry with you, do that and go walk the dog (or the cat, or the neighbor's ferret), do some housework, whatever -- anything that needs a little bit of your mind and a lot of your hands. You can keep the eGo in your pocket and pull it out when you want a puff, but then put it back and keep doing things. If you can't detach it and carry it around, get involved in something engaging at your computer -- a game, a chat conversation, a really interesting comment thread -- that makes you put the ecig down to operate the keyboard/mouse/controller and go to the tiny extra effort of picking it back up to take a puff. We don't want you overdosing. Stomachaches, acid reflux, jitters, and all the other smoked-too-much symptoms are easier to get to with vaping, because you don't have your lungs protesting the abuse to slow you down. So don't focus on vaping to kill the cravings -- just make sure your hands are busy, but your ecig is in reach. It's better if you do something you enjoy, to help form a positive association with vaping.
You're vaping, and you're here where folks can help you figure it out, so you're already doing the main things right. Everything else is details.
