How to get a flatter stomach with my current fitness routine?

Okay, so I eat healthily and probably a little less than I'm supposed to but my health is okay so it's not that. I also go to the gym everyday for at least an hour. There I will do around ten minutes on the cross-trainer, same for the rowing machine, same for floor exercises e.g crunches and the plank etc, the rest all varies. I did run a mile every time I came to the gym but my legs were quite weak and I would often pull a muscle so I stopped that. My first summer holiday is on August 13th giving me six(ish) weeks to pull myself together! I want to tone up, and especially get a flatter stomach! Any advice at all? Nothing is really working so far.....