You need to improve the tone of the muscles in a rhythmical manner. If you do that with proper diet
restriction nothing will happen to you. Body pain
is there after gym activity due to tiredness and you need to consume good protein
diet in your body which will help you to break the fatigue
and body pain.
You have to reduce the weight by walking minimum 3-4 kms per day. Slowly reduce the weight and slowly avoid adding salt in the diet which will help you to prevent water retention in the body. Excess salt in general leads to water in the body which might be the reason for you legs to pain as the leg will automatically become oedematous.