Thats great. A personal trainer will do you wonders, they keep you going and going. I am doing a body for life challenge at the moment - it is just healthy eating and lots of gym and cardio. I feel pretty good for it.
The worst thing is thinking you are on a diet. You are not dieting, you are simply improving the nutritional value of the food you eat so your body gets what it needs to do the right thing by you. I hate to think of dieting and what I cant have. I always say to myself, if I really want such and such I can have it after I achieve my first goal or in 12 weeks etc. Usually by the time you wait for it, you dont want it anymore and you find Sugar will no longer tempt your tastebuds but be sickly sweet.
Anyways I wish you all the best of luck in your endeavours.