I won't lie to you when I say that losing weight is probably the most difficult thing you will ever do in your life. Why? Because it rests upon the decisions you for yourself and if you have the will to push through the mental barriers you have set up for yourself since you were consciously aware of the way food changed your body. Excuses fall under this category.
For me, the first 2-3 months were the hardest! I was constantly sneaking snacks that were bad for me, thinking about food and munching at night and telling myself that I can 'always exercise tomorrow or pick up next week'. It wasn't until I caught myself making these choices and pushed myself to say no.
You will get cravings--I did--but it's all about saying no to those compulsions.
If food is one of your weaknesses, my advice is to cut it out of the house completely. If you like with others, tell them to name the foods you binge on. Hide food or put it in a place where you have to walk a distance to get it, giving you enough time to tell yourself to leave it alone. As for exercise, perhaps giving yourself smaller goals will help give you motivation? If you are feeling tired, commit yourself to 10 minutes of exercise. When you get going, you won't want to stop.
Try not to think about what you are doing as 'weight loss' and think of it more as a 'lifestyle change'. Think to yourself, 'these are the foods I am committing/omitting for the rest of my life because I want to (insert your reason here)'. Perhaps writing notes to yourself, post-its or A4, to remind you via positive messages to keep you on track. Don't think of where you are as a failure, think of it as a learning curve and that now you know how not to lose weight.
Get back on that horse and keep achieving your goals! We all believe that you can do it.