Welcome aboard the forums Craig
Motivation. Hmmmmmm. Tough one.
The first thing I've learned is....it's gotta be YOUR motivation. Whatever mine is won't work for you. Your wife/girlfriend/mother/best mate/someone on this forum can't make you want to do it...only you can
The next thing I've learned is...it's got to be real...tangible...something you can see or touch. For some it's an event (eg a wedding they want to be beautiful for). For some it's medical. For me it's similar to yours...I want to buy clothes from a "normal" shop (In your signature you say you want to buy clothes off the rack )...So how about a photo of some clothes you want to buy...go buy a magazine or tear something from a catalogue that you REALLY want to wear. Stick the photo on your bathroom mirror or the fridge or the front door so that you see it ALL the time...then each time you want to eat the wrong thing or be lazy instead of exercise look at the photo and ask yourself "do I want to wear that or be a couch potato?"...at the same time say to yourself "I can't have both". If a photo won't get you motivated go buy the article of clothing itself in the size you want to be!
I guess what I'm saying is think really carefully about the reasons YOU want to lose weight...not some vague notion about "being healthy" but the REAL reasons...it's likely the real reason is embarrassing. Like for me it's tied up with the fact I was once picked for a national swimming team and now I would be too embarrassed to wear a swim suit in public
Once you've been honest with yourself about why you feel the need to lose weight it will be easier to motivate yourself.
I'm not saying you won't still have hard days...you will. You will also have days where nothing
gets you moving. But if you are honest with yourself and keep reminding yourself of that personal goal you have it will get easier and easier to make the right choice more often than you make the wrong choice.
I also think you need to set small goals and rewards (not food ones) at regular intervals. EG...5kg lost = buy something for yourself (book, CD, computer game, bottle of nice wine...something you like that you don't buy often or don't do often). It's good to have an ultimate goal but if that's a long way off you need short term goals to keep you motivated. Well I do anyway.
My final piece of advice...don't get cocky about it. I know I've done that before and it's so easy to slip up when you think you've got the whole cravings/couch potato gone thing under control.
I'll stop rambling now