Many of us here know how you feel; we've been on many diets, only to gain the weight back again and often with interest. That's why so many of us here know and say that you need to find something that you can do all the time, that is comfortable for you, that you could do for the rest of your life.
The problem with the original idea behind diets, is that they were only meant to be short-term and for emergency cases, but in time, they evolved into what we now have today ... many diets and plans. I like some of the ideas from the Beck Plan also; I have found it very encouraging and helpful: esp to understand the 'whys' and 'hows' of overeating (identifying our triggers and how to deal with them in a practical way).
Each person must find what works for them -- I am doing an EZ portion plan which is "loosely" based on the calories of the average female (about 2000 C's a day). We still eat what we want and what we like to eat, for the most part. I took all our favorite meals and made them healthier by using lean meats, good fats, switching to complex carbs, and adding lots of veggies.
I really think that portion size is so important for many people -- hence you will be eating less calories without even thinking about it. Personally, I just find it so much easier for me. From all my years of dieting, I already know how many calories most things have, but I found that portions just suited us better.
How do I do our portions? I measure everything now -- try to find yourself a good set of scales: they are worth it. I use measuring cups when dishing out our servings; and I do this without even thinking about it now.
We are now eating soups and stews in bowls more often. One of my newest strategies is to have soup for lunch or dinner every day; with a slice of whole grain bread or roll, this is a light but easy, healthy meal. Right now, I have a beef stew (thick soup) in my crock pot; just tossed in leftover roast beef with a mix of veggies, water, and soup base. The house is filled with the aroma and it is cooking itself while I do other things.
We do this with soups, stews, chili, pasta sauces, etc. If you work, you can prepare the veggies the night before and just put the crock in the fridge until morning and turn it on to let it cook. One friend used to do this for the weekend when she was home; you can even do a pot roast in the crock for Sundays. During the week, you can do things that are quicker.
If you decide to try calorie-counting again, you can buy a little pocket book that has all the foods at your fingertips and the amounts, calories, etc from a bookstore. I have one just for general reference (ie snacks) that was published by DELL Purse books; very small and handy.
I try to get in some kind of 'MOVEMENT' each day; doing anything that I can think of that burns energy, with walking as my #1 choice. Plus I do toning work every morning upon rising; and try to do my walking early in the day also (even if it's only a short walk) as sometimes, I am too tired later on and may skip it, if I don't. This strategie has helped me a lot; and is fast becoming a new good habit.
We all struggle at times, we all have ups and downs; we all have stalls or hit plateaus; but the important thing is to keep going. The old adage is true for me: Practice makes perfect! I have much more discipline now than in the past. I have found that there are only a few things that I just mustn't keep in the house or I will be tempted to overdo them, but I may buy ONE SERVING of that item now and then, so I don't feel deprived.
I love pizza; but now, I won't have it unless it is on a thin, whole wheat crust, and smaller portion with lots of veggies. I believe you can eat good-tasting food and lose weight, and be healthier. What are your favorite foods? How can you prepare them in a healthier way?
I have taken the best tips that I have found from numerous plans and caring people, and added them all to my new healthier lifestyle. If it works for us, I keep it; if it doesn't, I toss it. Yes, GOD wants us to be healthy; yes, we want to be healthy; but I also remember, that GOD wants us to enjoy life too!
Remember, this is a journey of many steps; starting today, one day at a time. Forgive yourself for the past; look towards the future instead. Think only about today; that's enuff for us really. No need to obsess or worry; just eat healthy.
After many years of reading the bible and like you, doing many studies, I found this is what the bible says to me about eating, in a nutshell (and I am paraphrasing and condensing): "EAT GOOD FOOD; JUST NOT TOO MUCH!"
Will gladly send up some prayers for you.

Don't give up -- there is always hope ...
EDIT TO ADD ~ ANEWCREATION has a good idea there; maybe that is what you are looking for -- very simple and EZ! Many people have had success with it too! If you can't afford that for all your meals, you can buy lean quisines or other brands from department stores for less, for your lunches or an occasional dinner.