[Spellbound]

If you're concerned about your dog, I think the best thing for you to do is take him to the vet. Also, take him on walks, don't feed him as many treats or scraps from the table (if you do). If you take little steps to make him healthier then you won't have to worry as much!
And it's completely normal to worry about your pet like that! I know that I do. Pets are a part of the family, if you care about them enough. And it's great that you do care about him so much.