I hit my chest on something since then am having ...

What is the treatment of Back and chest Pain ?
Clinical assessment in the nearest medical center as you have to exclude cardiac diseases such as angina and ischemia and in other cases your symptoms might be duo to muscle disease and you have to avoid prolonged standing and apply water compressors for 15 minutes three times per day with Diclophene Gel three times per day to releive pain and inflammation of the muscle with analgeisc when necessary as Ibuprofen or Panadol Joint three times per day . 
You need to do clinical assessment in the nearest medical center if your symptoms presisted despite following the previous tips
What are the causes of Back Pain and chest pain ?
There are many causes for back pain , which include :

• Arthritis
• Herniated Disc
• wrong posture
• Muscle strain
• Muscle disease
• Other causes

What are the Investigations needed for Back and chest pain ?

• Clinical assessment
• X-ray of the back
• ECG of the heart 
• CT Scan of the back
• Other tests