Question on contracts

Hi, just need clarification on a contract that is already signed and if anything can be done still to revise some items.

So we signed a contract leasing a space for a percentage of sales. I am the lessee. Prior to signing the contract, I ran different sales scenarios and most of the results I’d say were fair for both parties. Therefore we ended up signing the lease. A few days after for some reason I decided to consult with a family friend and he pointed out a few things I missed. Which is on me, and not the lessor.

Now I know the contract is signed so we might not be able to negotiate anymore. But is it still worth trying to ask? Or do I just back out and forfeit the security deposit to avoid future loss. Maybe I’m just paranoid that THAT certain scenario will happen and screw up my plans.

Any help would be appreciated.