I am exclusively breastfeeding my 5 months old baby since last feeling I m having a painful red spot inside the skin of my breast is it ok to feed him?

Usually. If the painful spot is not an ulcer, it is ok, but you should follow this spot. If it increases, stays painful, or you develop fever, please see a practitioner to eval for possible breast infections (mastitis).
Yes. But don't forget to see your doctor as usual for any problems related to breast masses or breast-cancer.