buono - don't lose heart. You can do this, you just need to find your motivation.
Try writing down what your reasons are for losing weight it might help you see things more clearly and regain your focus. Also if you need to exercise try something that you enjoyed doing when you were younger. Revisiting that might make you enjoy exercise. You can always try taking a class or picking up a DVD that involves dance if you like to do that - that was what worked for me.
My motivation is health related. I'm not worried about not being thin etc. It's more that I don't want to have the health problems that my parents have. My dad has angina, my mum had breast cancer (10 year survivor!) and she also has arthritis which is affected by her weight. Some friends of mine have knee and joint problems and are borderline diabetic and they are not even that old yet. Some of my family members are diabetic and my mum's sister had osteoperosis and IBS. I don't get wrapped up in worrying about all of that but it is the reason I want to take care of myself now to increase my chances of having good health when I get older.
Having said that I'm going with more of a whole foods diet and a holistic approach to taking care of myself and my exercise focuses on strengthening my body (yoga, pilates, bellydance).