Ditch some of the machiens and also focus on lower body as well.
You can use some thing like Pec Deck and smith Machine, but definitely void things like a Bicep Msachine.
Start incorporating more free weights, so get an instructor to sort you out with a basic total body workout, like novices would get and then you're in a position in the coming weeks to step up the intensity a little bit with the weight.
As for the diet, stick to 6 meals a day around 2.5-3 hours apart to give your day some structure.
You have some simple options to help you with meals.
1. Have a protein source like Chicken, Turkey, Egg, Ham etc and a Carb source, like Fruit, Veggies, Grains etc.
2. You do the same thing, but incorporate something with a mix of Macronutrients in there, like Peas, Beans, Lentils, Mushrooms, Peanuts, Low Fat cheese, Rice etc, and remembering the Protein and Carb in them, reduce the amount of the Protein and the Carb source(s), to allow for that.
Fish is fine, but limit to 3x a week for Tuna as per current guidelines, or lower mercury Fish a bit more often, but don't go overboard on the serving size. Around 100g, (3.5OZ), a day for that should be fine.
I could have given you a preset eating system I used for other people, but I thought some general guidelines would work in this case.
So use the reccomended modifications for diet and workouts and see how you get on