Daily i am swallowing lot of pencil leads. does it leads to cancer?

No. This material is graphite which is relatively inert. It would pass out in your poop in a few days.

No, Get iron supplement. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines