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Keeping in mind that recent tests including a ultrasound, Chest X ray and blood tests have been normal, it is possible that your symptoms could be due to functional disorders.
Mental or emotional factors in many cases can produce physical symptoms - like headache, chest and back pains, tiredness, dizziness, bloating, etc.
Some conditions producing such symptoms include - chronic fatigue syndrome, fibromyalgia, etc.
Other medical conditions which can present generalized body pain - include - musculoskeletal disorders like costochondritis or musculoskeletal inflammatory conditions.
You might consult with your doctor who can rule out such conditions and provide proper help and advice.