hey man i respect your for all your hard work with being out of the military, kids, school and pursuing pool etc.
my personal opinion is that it can be a state of mind when playing pool. if you let it bug you, then it will bug you.
but gaining weight is something that always bugs me, and i have gone through my ups and downs with maintaining good weight. everyone does. especially whenever you get an injury. which i have had a few, and i am still keeping some of mine under check. i recently developed lower left back pain this year, and it got bad there for a little bit to where it affected my walking. but ive got it under control now and have been jogging now for a few months.
everyones injuries are different, but here are some things that helped my back pain. some stretches i found on youtube helped a lot, and i found that sit ups helped my back pain a lot as well. i have heard yoga can be really good for back pain, i was personally doing capoeira angola, my buddy is almost a master, and i trained with him for a few months, and my back pain would go away every single time i went in. its kinda like a slow moving yoga. i think my back pain is more of tightness rather than a sharp pain though.
since it sounds like you have a busy schedule, and if you cant find time to get a consistent work out schedule going, then i would highly recommend dieting. which you said, you love eating. i love eating too, i personally think that dieting is harder than working out. i boxed amateurs for 7 years and i come from a family of heavy eaters, and it is very hard to diet in my house hold. i would have to lead by example, and personally go out of the way to spend more time in the vegetable section, and cut down on the breads,meat, dairy, and carbs. all of which i love dearly.
to conclude, i think that when people say pool is a game, which i mostly agree with that it is a game. but i also think that a person who is physically in shape, has an advantage when playing. i think you will be less stressed, not as worried about a loose gut hanging on the table. look at earl stirckland, i think he is playing a lot better because of the weight he lost and he is working out a lot. just a lot of benefits in life to being in shape and dieting well.