Hello everyone.
I read everyone's post. I found them really helpful.
I didn't reply till now because I went to adjust my play.

I did start to continue when I m winning.
Last Friday I went to my local casino, I won $110 playing 3/6 (4 hour session) Then I went to take a hour break(had some good food). Comeback made 80$ in another 3 hour.
There is some clarification I want to make when I said I stop playing sometimes when I m winning: I usually play on weekend night, the player are most recreational player and retire ppl. Sometime I stop play because I m tired. Also I stop play when most ppl leave and I does not play well in shorthand. Sometime I comeback from my long break (usually way after midnight), they are playing shorthand table or everyone at the table only have $30 in front of them( min buyin is 30) usually at that point they play very tight and after one reload usually they will leave.

I notice

Also I did have some intention to try higher limit.
At my area, casino either offer 3/6 or 4/8. Then there is one place offer 8/16. So trying higher limit actually have a little gap. I tried 8/16 a few time, I put up 600$ as three bullets. And it seems like a rower coster where I lost first two bullets and the third bullet give me 200$ profit. I have not continue that 8/16 thing. But I think it is very profitable.