Carroll, who has been blighted by injuries this season, scored his second goal of the campaign on Monday night as the Hammers earned a 2-1 victory at the Stadium of Light.
The 25-year-old England international now admits that he is feeling close to full fitness.
"I'm feeling really good," he told the club's official website. "I've had three 90 minutes in a week, so I couldn't be any fitter to be honest.
"Obviously I'm a bit tired but we get enough rest and do the right things. All the lads are a bit tired, as you've seen at the end, but we're working hard.
"It has been a tough season for me, not being fit, but now I've got a couple of goals, a couple of assists and I'm feeling great."
Monday's win saw West Ham move 11 points clear of the relegation zone with six games left to play.