Best way to improve my game?

[ANY2CARDZ]

Ok, i started playing online about 1.5 years ago, started on pacific, and after a couple thousand hands, i was playing 15-30, i got my bankroll up to 5000, thinking i was great, cashed out 2000, and lost the rest. back to reality, i jumped around on different sites, mostly played party, and played limits between 1-2,and 5-10 sometimes 10-20, i always seemed to cashout what i deposited and the would lose the rest. Always breaking even. Then i stumbled onto bonuswhores.com in march, threw 1000 into neteller, and went to town, I cleared about 20 bonuses and fisished in the positive for all + i received the bonus, i cleared them playing mostly 1-2 2-4, 3-6, full games . I got my account up to about 5000, and then hit a bit of varience, i couldnt seem to have a winning session. I can never seem to stay consistent in my limits, and i know i can beat 1-2, and 2-4, my stats for 1-2 are about 4 bb/100, over 8000 hands, 2-4 may be around 1 bb/100 hands, i played at so many sites that i couldnt inportant many hands, and my computer crashed 3 months back, so i lost all my hands histories. When clearing the bonuses i would usually 3 or 4 table. So i found that I dont really know what limit i can consistently beat. My bankroll is inflanted because of the bonuses, around 3000 right now, i guess that sufficent for 3-6. So ive signed up for rake back on empire and i want to stick to just clearing the odd party bonus, and mainly just working on my game, and try to work my way up the limits figuring out what i can beat. My 6max game is very weak, i can beat the 1-2 game on party but other than that it needs some seious work. So im looking for some advice on where you would suggest starting, i was thinking of going back to 1 tables, and starting on 2-4, playing a few thousand hands, and moving up when ever i have earned 500 bb at each level. I know bonus whoring has made it easy for me to just go onto auto pilot. What have you guys done to move up limits in the past, should i stop multitabling all together and wait until i know i can beat the higher limits. Or should i start on my short handed game at 2-4 and try to move up through that? Any adivce would be greatly appreciated. Cheers