My time to shine
Right you say you don't have enough time but I'm sure you have 20 minutes before you go to bed
Squat for 12-20 reps for 3 sets
Press ups 8-12 reps for 3-5 sets
Crunches 12 reps for 3 sets
(Have 30-60 second break between sets
There's your very basic workout for every other day or every 3 days depending on if you still hurt or not. If it starts to get easy add another set to it.
For diet drink around 2-4 pints of water a day. Drink water with a meal aswell as it will fill you up quicker. Don't go for diet drinks as they are usually pumped full of chemicals that would do your body more harm than a bit of sugar. If you do want a energy drink go for the Neuro (sonic is my favorite) drinks as they are a 'vitamin and herbal beverage' that I fine give me a massive energy boost at 37 calories.
Reduce your salt intake.
If you feel hungry between meals snack on some cashew nuts as they are really nice and healthy
If you do go to get fast food don't eat the bread with it you may look a bit strange but that will save about 200-300 calories a burger.
I found that if you eat 2 high fibre breakfast bars for breakfast they usually fill you up until lunch if not have another they hardly have any calories in them.
Buy some multivitamins (PM me if you want a good brand that uses safe ingredients) They will top up your vitamin levels that your most likely not getting enough of and this will give you lots on energy.
Fitness and nutrition is my not so very secret anymore hobby