Find a good physiotherapist (hard to find) who can help assess the balance of the muscles in your body. A good physiotherapist will help you to strengthen the weak muscles and stretch the tight ones.
Get outside and run around a bit, kick your shoes off, goto the park, run around get your body moving, the body likes to move. It's amazing how much better you can feel within a few weeks time just by opening the body up to the world a little bit and giving it some room to breathe.
Even when you are walking down the street think about how you are opening the front of your body up and not hiding/shying away. Do not strain the boyd however, do not force it into good posture, just simply gently open yourself up and give yourself some room to breathe physically and mentally.
Do not stress, fixing any health issues will take time and patience, any stress takes away from progress. the answers will come through self experimentation and close attention to how activities affect your daily sense of physical self. Keep a journal and connect the dots.