How long does it take for costochondritis to heal and is there any stretching i can do to help speed up recovery or anything i can do to speed up recovery? thanks?

Costochondritis is a result of a muscle injury and subsequent inflammation. Ice, rest, NSAIDS (such as motrin/advil) can help to reduce the inflammation while the muscle heals. Healing typically takes 2-3 weeks for a mild injury, 3-4 months for a severe injury. Stretching will not help and may actually reinjure the area. Rest the muscles involved and if you must exercise, do non impact walking.