Shrapit yoga is a fake yoga invented by wayside astrologers and there is no classic reference to it in the text books of astrology. You need not worry about it at all. Yes your sixth house is very weak and that could bring some problems with Debts, Diseases and Enemies in your life which has nothing to do with Shrapit Yoga.
For more details go through my blog. “Myths and Misconceptions in Astrology” is an article which will help you understand about many such frightening doshas which has no basis.