hi, it sounds like you are in a parallel position with people who try to lose weight. it's very tough to stay dedicated day in day out and may take many months to get in a long-term habit of doing it. my brother is in a similar position as you. he is 6'3 and needs to work very hard to stay around 190 (constantly being at the gym and getting in extra protein), and drops to 170 very quickly if he doesn't maintain his routine (he is in that lifestyle now).
your diet needs work, you need to train yourself to eat. good carbs and lots of protein. meat cources are very high in protein, i'm sure you know. (chicken is great becasue it's low fat too). maybe cook a bunch of chicken once a week so its handy and you don't have to worry about the extra time it takes to cook. rice is great as well. canned fish if you want something quick; for instance canned sardines(in oil)/serving pack 190 cals, good/necessary fats, and 20 g of protein.
try buying protein bars to bring around with you too. eat small meals every couple/few of hours (you can usually sneak in extra cals this way as opposed to eating 1 large meal/day). do you eat sandwhiches? load them up with cheese; find ways you can add protein rich foods in your diet.
of course you will not stick to this every day, but try for maybe 1 day/week and eevry week after add a day. or try for more days eating like this and not. sounds like you are great in the working out department. within half an after a workout, a combo of protein and carbs will help repair the muscle tissue you have broken down during the workout (ie/ protein bar, or a balanced bar, and an apple). you want to do this.
running on the tread or going on the elliptical will help your stomach prob. you can't spot reduce but running is great at melting ab fat.
also what may help is get weighed at the gym. often they can assess your lean body mass as well as fat so you can chart your progress and make sure your muscle mass # is growing.
set specific goals. really be diligent about this.
so for example,
-stock up on healthy groceries
-eat 4-6 meals/day, with at least X amount of protein at each one, and a healthy carb.
-do 3-4 weight lifting workouts
-eat within a half hour of leaving the gym
-carry protein bars with me so i have easy access
-get muscle mass assessed.
-research muscles and body building on the net (not saying you have to be a body builder, but i'm sure there are tips for body builders that can help you)
anyway set whatever realistic goals you want, write them down. look at them religiously, and write down how your day went compared to the goals you set. kind of like a journal.
good luck, i hope i've helped, and let me know if i can try and help you with anything else