For years now I've constantly felt sick/nauseas after I eat a meal, usually at dinner time, whenever I eat proper foods such as potatoes, chicken breast, certain meats like mince, steak and beef, I could eat all the junk food in the world and feel fine, I can eat Birdseye crispy chicken (could live on the stuff) fast foods such as McDonald's, KFC and Burger King, I can eat take aways and chip shop food and nothing, it's like home made meals made from scratch don't agree with me, any suggestions?

Not possible to diagnose just from that. But you asked for suggestions, so I will suggest that you are merely just gassy from a home cooked meal with VEGETABLES?? You mention meat, meat, meat, with one vegetable, potato, but it's usually the green veggies that cause gas, and if you don't get enough healthy diet, it just gets worse. It means your gut flora is being ruined from lack of the very foods that are causing gas.

Now I could be totally wrong, because gas and nausea are two different kinds of discomfort. So tell us more, a LOT more, starting with age and gender and where you get healthy foods in your diet. There certainly plenty of other conditions that cause nausea, but you say this is a difference of home cooking and fast food.

I'm 20 and female, it's been like this for over a year, I've usually got a side of veg with meals, or veg mixed through the meal, sometimes I won't have any veg with meals but mostly I do

Try taking 1/2 teaspoon of unrefined sea salt (e.g. Celtic Sea Salt or Redmond Real Salt) with a small amount of water. It should eliminate your problem fast.