Sherwood lost his first game in charge against Stoke City last weekend, with a last-gasp Victor Moses penalty giving the visitors victory after Ron Vlaar was sent off for a foul on the on-loan Chelsea forward.
Villa sit second bottom of the table with just five wins and 13 goals to their name, and Sherwood - whose side visit Newcastle United on Saturday - is under no illusions as to what they need to stay up.
"Is it a bigger challenge than I thought? No," he said.
"We have won five [league] games of football all season, we need to win six to stay in the division.
"The reality has to kick in that we are in a dogfight here and we need points as soon as possible.
"It's a work in progress now and I am just trying to identify the strengths and weaknesses as soon as possible.
"I'm learning all the time about the guys. If we can get as many points as possible we are going to fail trying, that's for sure."
