Hi Annie!
I did a sort of modified Atkins/South Beach low carb myself, which worked well for me. I didn't actually count carbs nor did I ever wee on a keto stick

. And i did have foods you're not supposed to have such as the occasional glass of wine, my daily cappuccino (coffee addict), summer fruits/berries from day one, unlimited green veg.
I know exactly what you mean about not being able to stop at one slice of toast. It's like a bottomless pit! It's different for everyone but I found that cutting out all sugary, starchy foods - bread, pasta, rice, potato, root veg, most fruit - took away those cravings completely - out of sight, out of mind.
I find that low carb really suppresses the appetite (keeps your blood sugar and insulin levels constant) and that's a godsend for the willpower, which is what it's ultimately all about!