I weigh 77.8 my height is 156cm. i have large breasts which causes back, neck, shoulder, arm pain. is it possible for me to go for breast reduction operation? i have been following a healthy diet and managed to loose 5kgs but my breasts remain huge.

Possible: I would consider conservative therapies first such as strengthening exercises for your core. Also look up exercises to strengthen the upper back. A good book for exercised to help with pain is Pain Free by Peter Egoscue. Consider chiropractice or osteopathic manipulation, accupuncture, massage.....If conservative therapies don't work then follow up with a breast or plastic surgeon.