Do the opponent's cards scale with your level or what? I think I didn't spent enough money on cards and now even the cheap dates are all outleveling me with their cards :(
Yes, in 0.08 and prior, it does scale with you but in 0.09, the upcoming update, we've overhauled the SMS system so that levels don't scale with you, instead you gain stars through the star rating system (how well the date went) and use it to unlock harder levels, so even if you feel too underlevelled, you'll be able to go back to easier dates and grind from there at your own pace.