I'm 250. In great shape and 39.
Been doing vacuums. Make sure you are doing the hard enough. Like it should be all you can do. If it's 30 seconds or 2 min... Pull hard.
Take 1 thing out at a time that you think my be giving you probles, eggs, milk, shitty whey protein.
Try a digestive enzyme or probiotic.
My personal favorite, is dnp at 500 mg. By 10 days in stomach is flat. But, still a little rounded. Way better. I diet hard on dnp. 2800 Cal's an drop, training is same an intense, hour of moderately hard cardio. I lost 22 pounds last run. If you're not advanced, don't try it....