Susie's answer covered everything perfectly! Coke zero is preferable to diet coke - but if you're using lemon, lime or robinsons then you're having citric acid anyway. Just be aware if you're losing slower than you'd like that those items may be to blame.
Stay away from the Atkins crackers! Definitely don't have them in induction but in general Atkins products are best avoided as long as possible. If you're missing a crunch you can make cheese crackers - grate cheese into small piles and put on baking parchment - microwave until crisp
Or salami crisps, slices of salami grilled until they're crispy like frazzles.
Or flax seed crackers - mix flax seed with butter and a little egg white, press thinly onto baking parchment and pop in the oven.
It's always always best to go for food you've made yourself from natural ingredients.
Welcome and good luck!