A cup of sugar is most definitely *not* equivalent to the daily required intake of joules (or, calories, depending on your units of measure). 1 cup of sugar (192g) contains 720 calories, or 3014 joules. A 6' tall, 50-ish male who weighs 190 lbs and is lightly active can expect to burn 10406 joules per day (2485 calories).

It sounds like you are on the right path, but are a bit impatient. As others have pointed out, you did not get overweight and out of shape overnight...don't expect to lose your excess weight and get "buff" overnight either. Successful weight loss requires patience and persistence.

For long term success, you need to achieve a modest daily energy deficit. A deficit of 500 calories per day (2093 joules) should result in weight loss of about 1 lb (0.45 kg) per week. This is considered a safe, and healthy, rate of weight loss. But, even smaller deficits can result in substantial weight loss if maintained over time...and, they're easier to achieve.

As for achieving the energy deficit - it can be done via dietary control, or exercise, or (ideally) both. But, be aware that dietary control is far more important than exercise - it's very easy to subvert a good exercise program with a few poor food choices.

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