Loosing weight can be summed up quite easily. It all comes down to an energy balance. If you take in more energy than you need you gain weight and if you take in less you loose weight.
In the end it does not matter what diet concept you follow, because they all have the same goal: Make you eat less than your daily requirement.
For an average male adult this is about 2500kcal and for a female around 2000kcal.
The flaw of many diets in e.g. magazines is, that those may let you loose some weight fast, but once finished you gain weight again. Why? Simple, because you return to your old eating habits.
The only way is a change of your habits and the way you eat and prepare your food. What works for many people is eating food with a relative low energy density. This gives you the feeling of eating a lot while not consuming an enormous amount of calories.
In fact, just to make it clear, I recently came across a study where one test-group only ate fast-food (high energy density) for 4 weeks. This group ate a controlled amount of calories per day and none of them gained weight and all their vitamin/boold levels remained perfectly fine, but they said that they felt hungry all the time.
A better approach is to stick with what is generally called Mediterranean cuisine incl. low fat meats (e.g. chicken), reduced fat milk, little oil and butter, some pasta (wholegrain), etc.
I personally think that any special products in supermarkets (powders, shakes and what not) only decrease your account balance and don't do anything good.
Sticking to what I wrote above, it is allowed to sin a little. Eating a fattier meal one evening a week or sweets it is ok to do so if you balance your overall energy intake.
Some additional exercise is unavoidable if you want to speed up your weight loss. Try to find a sport that you like. A gym or running are not the only sports around! Try a few things, most places offer free taster sessions.
If you want to give running a go, try the c25k (couch to 5km) program. It is normal that you can not run for a very long time at the beginning. You did not mention you weight. In case you are very heavy do not hesitate to consult your doctor before picking up an exercise program.