Several others have said it, but I want to chime in because who doesn't love a dog-pile of praise and encouragement?
You're doing GREAT. You've cut down from 30+ cigarettes to 4-6 a day. That's HUGE. Don't let yourself get discouraged because you haven't given them up yet completely. For some people it's harder, because every brain is different, and that's where the addiction is. Every cigarette not smoked is a damn victory.
I agree that you probably need to up the nic concentration in your juice, and tweak your PG/VG ratio to compensate. I get a satisfying throat hit with a 70/30 mix, but your mileage may vary. Heck, mine might too - I'm still pretty new at this, and ordered a bunch of juices in different blends and strengths, to try and find exactly where my sweet spot is.
Also, what Ryedan said is absolutely spot on. The physical action of vaping is different than smoking, and if you're inhaling the vape straight down like you did your analog, that may be contributing a lot to the harshness. Draw the vape in with your mouth, let it linger in there for a bit. Then, if you really feel the need to inhale, go ahead.. but you may get to the point where you don't even need to do that.
Finally, it might feel weird at first vaping when other people are smoking. They might give you strange looks, ask you lots of questions, or even try to tell you that vaping is just as bad or even worse than smoking. Don't let the uninformed opinions of others get between you and your goals. Educate yourself, from here and from the CASAA.org website, and talk with your friends/neighbors about it. You may convince them, then convert them, and have your own little vaping group! If not, don't sweat it - you're doing what you have to do for you.