Still have large belly

When you mean "belly", do you mean mostly if not all fat, or mostly "bloat" ?
If it is mostly all fat, then, a combination of a very low-fat diet with proper weight training (moderate, targeted and effective), three times a week, and moderate aerobic exercise, two to three times per week (45 min or more, allowing you to still being able to speak while doing it) will "burn out" said fat as energy during training, without leaving your abdominal flesh loose and sagging, like a deflated balloon would look.
If it is more of a puffiness, or a "bloated feeling", then, it is a matter of food combination. It is crucial in that case to avoid the "sandwich syndrome", namely, that any protein tastes better if it is consumed between two slices of bread.
Instead of a balanced diet, use a segregated diet, namely, at one meal, have your protein, from animal and dairy sources with green vegetables and no starches (either grains, rice, potatoes and corn) or fruits, then, at the next meal, have fruits, vegetables and starches with non-animal protein sources (beans, nuts), or zero-fat unsweetened dairy products. Thus, no starch consumed with animal protein and moderate to high fat dairy products! And plenty of fresh water (tea, coffee, juices and alcohol don't count as "water")!
Alternate this pattern of eating over four to seven meals per day, eating only when hungry.
Proper posture during your weight training and aerobic workouts will tone your waist in a gentle and efficient way, as long as you concentrate: --no slouching!
Regarding direct abdominal exercise, it should be avoided if you have done a lot of "ab-work" in the past, because it might create a thicker abdominal muscle wall, and still give the appearance of a protruding stomach, although with abs (!). If you have not done much of it in the past, choose upright moves such as alternate standing knee raises, standing waist twists, or "chopping wood", again, in moderation.
To complete, sleep is where fat is truly burned. Therefore, try to have six and half to eight hours of sleep per night, and you will be "eating your fat" while snoozing.
Why should not one only sleep then with no training, no diet? Because your organism would either eat off your muscle tissue to the point where your body would become depleted, with skin hanging off your bones, or, in the opposite, where your body would not only hold on to water within its fat cells, and on top of it create even more water (!) which might then turn you extremely fat, formless and bloated.
A balance between your food intake, training output, work-life and family-life is the key.
Visualize your desired outcome vividly and fix your mind on it.
Be persistent, do this with a smile! Prepare to make heads turn! Enjoy the process!