With all due respect, you need to give it time. You've made a huge change, and your body will need months at least to adjust to new caloric intakes and sources.

If you have to "go on a diet" instead of "have a diet" it is always going to be a struggle.

Find a nutrition plan that is balanced for your lifestyle - understanding this will change with time as you get older and have lifestyle changes (e.g. have a child).

Once you are in balance, what you call "exhausting discipline" will just be "how I eat everyday."