Charley also, eating fruit for breakfast, lunch and snacks with nothing else will play havoc with your blood sugars and will make it harder for you to stick to the diet and lose weight.
You need to eat your healthy extras. How about weetabix with skimmed milk and banana for breakfast?
For lunch id try to stick to veg instead of fruit so how about a salad or a soup? Try to have some protein too, e.g. Lean meat, eggs.
The SW ethos is that you are able to still eat properly and lose weight. You need to be switching to low fat, low cal and possibly smaller portions but you really can eat well on this plan.
Meal-wise, this doesn't feel like a diet. No, I'm not having many treats such as Chocolate, crisps, alcohol etc but I'm looking forward to my meals and feeling satisfied by them.
Eating fruit only might give you some quick results but it's not sustainable long term.
Everyone on here will help you if you need advice on how the plan works, post as much as you need and keep asking questions if you don't get it, there is usually someone around.
Good luck and welcome to you and all of the other newcomers!