I suddenly realize that I've become stagnate in front of the computer for more than ten minutes.
"ふと気がつくとpcの前で何10分もくすぶってることがある"
- I suddenly realize that I've become stagnant in front of the computer for more than ten minutes.
- All of a sudden I realized that I had become stagnant in front of the computer for more than ten minutes.
stagnant = stagnate adjective form
stagnate 例文：
The waters will stagnate after the storm.
嵐が過ぎ去ると水面は静かになる。
Sometimes I suddenly realize I’ve been just sitting at my PC for tens of minutes, stuck.
Sometimes I suddenly realize I’ve been just sitting at my PC for tens of minutes, stuck.
Before I know it, I’m at my computer for half an hour, not really doing anything.
「ふと気がつくと」は、英語だと suddenly realize / before I know it がとても自然です。
suddenly realize は「ふと気づく」、
before I know it は「気づいたらいつの間にか」という感じです。
アメリカ合衆国 
