You have to eat, that is, don't eat high-calorie food, such as pork or fat. Eat more foods with more fiber. Don't refuse spaghetti, or you won't have the strength.
About sports. Muscle relaxation is due to lack of exercise. Push-ups can be practiced with dumbbells. Get down, get down, and take off.
Full body exercise, preferably: skipping rope. I have practiced my legs and arms. After the training, eat fruit. Tomatoes, cucumbers and so on.
Wish you success!