Ahoy and welcome good sir!
A sporadic learning style can definitely make it kind of interesting for something as time-intensive as Japanese, but it’s super rewarding when you can manage to get yourself to focus on something long enough to learn stuff. I can be kind of ADD (for example, I’m currently 3/4s of the way through a pretty hefty Anki session and I’m stopping to write this) when it comes to studying and studying CONSISTENTLY so I can definitely understand the difficulty you find in concentrating.
I’ve found that going to Starbucks (or, you know, any other coffee shop, but Sbux for me) can be a pretty good way of making yourself concentrate. That isn’t obviously for everyone, but being a bit crap financially speaking, I can only afford to go a couple times a week so when I’m there I sort of end up working pretty efficiently. Also it’s fun when people are looking at you pound kanji into a notebook. Feels good.
Anyways, enjoy your time here!
I haz a blog http://maninjapanchannel.wordpress.com/
https://www.youtube.com/watch?v=qLQzB-1u-dg