I absolutely agree with the comments about eating less and exercising. For me the only way I can effectively shift kgs is to exercise. Also weight training is really good for losing weight. Sounds crazy I know but it's true. You won't end up looking like Arnie I promise!! Building muscle mass burns fat and when you have muscles they burn fat for you even if you are watching telly! Do it wouldn't hurt to join a gym (but only if you WILL use it) A gym membership alone wont do anything!!
Don't bother with fad diets, they may help you lose weight on the scales but it is usually water and muscle mass. Also when you stop the 'diet' you are going to quickly regain what you've lost and more. You need to change you eating and exercise habits to enjoy any lasting change.
Don't be too hard on yourself. It takes 21 days to break an old habit and 45 days to establish a new one! Take it slowly. Aim for around .5-1kg and week (1-2.2lb)
I find it very helpful to keep a food diary and have to show it to someone. (I feel embarrassed if I write down a whole pizza so I don't eat it!!!! However this only works if you are honest!)
Aim to eat 5 small meals over the day instead of 3 large meals it will get your metabolism working better also helping to lose fat. Also drink plenty of water.
Don't buy the things that you know you will eat cos they are there. I don't buy biscuits or chips etc for this very reason. If you must have chocolate or whatever your thing is, buy a small size and really savor it.
If you stuff it up, don't worry, start again at the next meal. You can do it!
Also do it for yourself. 'The only expectations worth living up to are your own'
HTH and Good Luck