The Vikings are hovering above the bottom four in Betfred Super League after losing seven of their opening 10 matches.
They are also struggling with an injury crisis that has denied Betts the services of nine senior players.
"You think you're going alright," Betts said. "We've done a lot of work to make sure we're pretty robust but it's a strange year again.
"It doesn't get any easier. Hull are a top-four side so we know the task in hand.
"We're not playing badly but we're not picking up wins. We're at the halfway stage and there's been three games we probably should have won.
"That's created little bit of anxiety so we need to start winning games to ease that."
Betts has called up 19-year-old forward Owen Farnworth for his second appearance - 12 months almost to the day since making his debut - while Hull coach Lee Radford is still without his entire first-choice back row in Sika Manu, Mark Minichiello and Dean Hadley, and has lost Brad Fash with a broken jaw.
"It's a lot easier to pick a side when we've got some bodies available, but we'll ride this wave and it'll make us stronger come the end of the season," said Radford, who has singled out former Hull hooker Aaron Heremaia as a danger man.
"Widnes play to their strengths," he added. "They put a lot of width on the ball.
"They've got some really good skills and Aaron Heremaia is playing like a much younger man at the moment."
Radford is able to bring back right winger Bureta Faraimo after completing his one-match ban and has confirmed that Fetuli Talanoa, Super League's leading tryscorer, will be on the other flank after recovering from a calf injury sustained in the defeat at St Helens.
"He has put his hand up to play and he will be selected," Radford said. "I'm glad because he's been in great form for us.
"It was a big blow for us and for him, losing him so early in the game last week, but he's impressed me with his willingness to take part this week."
Radford says his team have been training on a 4G pitch for the last month in an effort to familiarise themselves with the Vikings' artificial surface, where they came from 22-0 down to win 33-22 in the corresponding match in 2017.
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