Well, if youre playing calculating pot odds
unless you get incredibly unlucky you wont see a downswing in the long run. The thing is if you move up and not have enough money to make a difference ( Let me put that into simple words, I hope you will follow the pattern - If you have $2 in your BR and you play at $0.1/2 the things might not turn too well even if you make all the right decisions, because you only got these money. But if you had $20 in your BR it would be enough to make a difference in the long run ). So, if you have any money in excess, say you have 120-30 buy-ins for 2nl, you can play a few games at higher stakes and see how it goes. If you get lucky you will bring your bankroll to another level, allowing you to play at these stakes regularly, and if you dont you still will have enough buy-ins to play the lower stakes and still make it profitable.
If you find yourself winning now at 2nl you might aswell just hold on there, until you got the proper bankroll to move up in limits when you will be less worried about bad beats and losing streaks.
I mean that if I was winning at $2nl I'd stay there unless I got the proper bankroll for a bigger stakes. Then I'd move and if I am losing mostly I'd move back to the old limits.
Hope I did not misunderstood your question.
Also, I dont know whether you dont have the time to play regularly or it was just a really good planned schedule, but congratz. on sticking to it. When you play less hours a day its less likely to experience a tilt and lose money on hands you wouldnt be playing otherwise. I'm glad this is working out for you.