The home side were set a target of 350 in the second innings for victory, but were reduced to 57-5 by the close of play this evening.
The batsman, who scored just eight runs this afternoon, told BBC Sport: "There were a few things with batting and bowling we could have done better but we need to take our chances.
"The window into your team is the fielding and we have to get better at that. No excuses, we have to do better. Massive credit to Sri Lanka, they have outclassed us."
Bell is playing in his 100th Test for England.