The first time I tried e-cigs (a year ago), I was on 11mg and I didn't stick to it- although there were a lot of other issues at the time.
This time, I'm on 18mg and I've been analogue free for 22 days (and counting) although I too am chain-vaping. I was advised by people on the forum to up my intake to 24mg in a morning to get over the first cig of the day and that definitely helped. After two weeks, I unconsciously stopped the 24mg on a morning! Having gotten over the first three weeks, I'm now turning my thoughts to lowering my nicotine intake in the next couple of months because of the chainvaping...I can deal with the hand-to-mouth addiction later!
11mg sounds very low considering what you used to smoke! It might be worth upping the strength... that said, I've read plenty of posts on here about people enjoying vaping and the taste of their juices so they vape anyway. Try a 10ml bottle of stronger juice and if that helps, you know where you've gotta be. If not, it's there for dire emergencies and you've not wasted too much money. If higher strength works for you, you can keep the lower nicotine incase you feel ready, or that you want to, cut down further.
Three days is awesome- but imagine how good you'll feel when you make it to a week, or a month, or a year!

I have an app on my phone that constantly reminds me of how awesome I'm doing and the many health benefits...it costs it up and includes the costs of e-cigs in the calculation too. It's called aha! Smokefree from the android app store...I've got a widget on my phone desktop so it's always there to remind me. It's free and certainly helps me...maybe give it a try!