Sounds like you are a carb addict. I was - your rice is my bread.
Is switching to brown rice an option?
My suggestion would be stick with the beef, pork, and poultry. Toss the rice and pasta. Have more green vegetables. I suspect that the reason your stomach bothers you if you have a chicken breast and salad is because there is not fat in that and you digest it too quickly. Fat slows digestion, staves off hunger, and helps stomachs feel better. When I got off the rice, pinto beans, pasta, bread and on to the meats and green vegetables within 2 weeks I went from mr daily heartburn and 1 large bottle of tums a day to no heartburn in over 2 years now. It takes a couple of weeks to get past the carb addiction though.
This may not be your problem, but from your description it sounds like it.
Now for the other goals you mentioned. Start doing
resistance training (lift weights) and
cardiovascular exercise (walking, running, biking, jumping rope...)
Find something you like and can stick with.
And no - it's never too late to eat. I eat around the clock. If I'm hungry, I'll eat at 3am and go back to bed.
This is coming from a former 300 pounder who is now 180lb.
Good luck, I hope it works out for you.