Definitely look into proper BRM plan. Thats the first thing you should focus on because that is what'll hurt you the most. There are a lot of different BRM plans out there, but I advise you to figure out one on your own that you're comfortable with.
For example, with my BRM plan: I like to have at least 30-40 buy ins for any game I choose to play. So, lets say its $1 + .20 SNGs on stars, I'd need at least a $36 BR. So, if I hit a losing streak, the losses dont effect my BR as much. In fact, in the past 2 days, im down about $15+ dollars on $1 SNGs (bad run) but its ok because I had big enough BR to handle the losses.
Playing $3 SNGs with a $20 doesnt give you that leeway, because you will lose and every time you do, thats costing you about 15% of your BR, more if you include the rake. If you're trying to move up the money ladder, sometimes you have to take it slow and steady and build up gradually. Dont be ashamed to back down a couple of levels because of your current BR status. Whats worse? Playing penny stakes with a BR? or no BR at all? I've had huge swings where Im up playing $2 SNGs (BALLA!!!) to where I can only afford to play at max .50 MTTs. And there is nothing wrong with that. Its all about playing smart.
Try playing different games. To build up my BR to where it is now, I played a lot of freerolls on PokerStars
and Full Tilt. I also took advantage of PokerStars' .10, .25, and .50 MTTs. They're such a small percentage of my BR, but have extremely good pay-outs. I made $20 on a .10 MTT FT, so thats a big boost with virtually no cost to you.
ETA: Just saw your post on PP's $3 games being the shortest buy in. I read it as you were playing on PokerStars...whoops. So, you can ignore this but I'll keep it posted.