Hazel isn't impossible, just a little tricky. She's defensive-focused, so you don't need to worry too much about her attack. Use the Ramen/Pizza/Salad meal for an early push, and the Goon's "reinforce" tactic to somewhat even the odds.
Many more buffs and dice upgrades (temporary and permanent) will be coming in the next update, too, for people who are struggling :)
I have to put Ramen/Pizza/Salad because each player will only get one of the three, and it's dependent on what you chose to buy at the supermarket in the prologue :) All three do the same thing, though.
And no, no need to replay anything. All Meal options are available to you by default and future meals will be unlocked throughout Act Three. You won't be able to miss them unless you deliberately choose to.