so im trying to go on a diet?

i really want to diet, but i dont think my approach is really good.

now heres the problem, i work almost all day and dont have time for stuff like gym or sports, at work im pretty much sitting down the whole time, so i stopped eating alot of foods, i pretty much was eating this for the past 3 days, ad dont know if its very healthy, but i do feel a little better about myself, not cramming chips chocolate and fast food down my throat,

i have one slice of wheat bread in the morning, with 2 cups of water, then head out to work, at work, i drink coffee and water all day, when i get home i have another slice of toast and more water, but alot more water, like probably 6 cups, to stay full and from thirst. now i do have some oatmeal, and im gonna start eating that for dinner, plain, with a little olive oil, but is any of this bad for me? and why?

thanks for the help