It sounds like your singing needs some help. The best way to begin is by learning how to breathe using what is called "the belly breath or diaphragmatic breathing." I'm sending you a link to teaching you how to do this: https://hubpages.com/learning/TheMiracleofBreathin... Practice the exercises as outlined until your new way of breathing becomes automatic. Use this way of breathing every time you sing to support your tone. When your throat hurts while singing, this is a clear sign that the voice is being strained. I've also created an article on teaching yourself to sing: https://hubpages.com/learning/Find-Your-Natural-Si... This will help you, for now, however, I always recommend studying with a qualified vocal teacher.