It is nearly impossible to lose weight by exercise alone; the numbers just don't equal out that way. However, there are plenty of reasons to exercise anyway- both mental, physical and psychological. Most experts say healthy adults should aim for at least 150 minutes of heart pumping activity a week, but it can be in small bits at a time. A variety of cardio, strength and flexibility exercise is also recommended for most people; which also helps you stick with a variety of different types of exercise. There are more factors that allow weight loss including healthy food choices, adequate sleep, a healthy social life, satisfying relationships ect. Most of us here are struggling with weight in one way or another and balance in our busy lives is hard. Look at all the factors and don't give up.
Exercise is awesome, but diet is what plays the biggest role in weight loss. If you want to lose weight, you will need to cut calories out of your diet. Additionally, you might be putting on muscle. Muscle is more dense than fat, so the same volume of muscle vs fat will weigh more. Therefore, weight alone may not be a reliable indicator of health so you might try observing your body to see if you have lost fat and/or gained muscle. If you want to do this in a measurable way, you could observe how you fit in clothes, find a scale that scans body fat percentage, or use tools like calipers or a measuring tape.
Is your diet in check? You'll have to consider your body type. If you're the type that puts on weight easy then you'd have to try and replace sugary foods with healthy fats and protein. Up your protein intake and keep your carb intake to a max of 50 gms a day. You should see results soon enough. Your diet is key to looking the way you want
The issue with this question, is it is much more difficult to answer without knowing your genetic history, metabolism rate, your diet choices, and what kinds of work outs you are doing.
Lets start with working out. The best work out for weight loss is plain and simple. It is cardio. Anything that gets your heart rate up will promote weight loss. Weight/strength training will only build muscle (which will show up as maintaining weight, or gaining weight). Remember, fat and muscle weighs the SAME.
Your metabolism and diet have a factor in this too. Overall, losing weight means cutting down on fats and carbs. It is recommended that you don't cut them out completely and you don't starve because this will have adverse effects on you. It will NOT work. Try speaking to a doctor or dietician, they will advise that the best thing is reducing a caloric intake for weight-loss. (Don't reduce it too much. The average females caloric intake is 2000-2500 cals).
Your genetic history is important to. Ask your parents/guardians if they know anything about it. You may find out that your bloodline has a higher difficulty losing weight. It may even been an underlying condition that means you have to work extra hard. All you need to do is ask around, try and find some personal details, and go from there! Good luck!