It's true that the feeling of being "in control" in ketosis really is wonderful. I'm so sorry for you ref those darned tinned tomatoes.
You asked about skimmed milk allowance. In attack, there is no limit on dairy, but in cruise it's advised not to exceed 250ml (1/4 litre) skimmed milk per day, of your total 1 litre dairy. In reality, some find 1 litre dairy far too much and I try to keep under 500ml in cruise. You might find black coffee becomes more appealing as time goes on to enable you to use your dairy allowance on something else...
For the diet coke question, I try not to go over 1 can a day as I fight with a sweet tooth off Dukan so figure I'll try to temper it while on Dukan. Also I'm not a huge fan of sweeteners, so...
Green tea is GOOD!
Keep posting your menus. At your current weight, you really can eat lots of pure protein so ENJOY.
If you wouldn't mind filling out your profile, we can all see your height, etc and follow your progress easier... Nice to meet you and hang in there! x