sewing machine?

i need to fix timing on my singer touch & sew 626. I've been watching utube videos, but, not showing in detail enough. been working on it for 2 months. I messed it up by turning wheel other direction and touching screws to bobbin under machine. I'm so close to fixing it. Now the needle is scraping bobbin and getting jammed, & material was bunching up on back of material. I'm determined to fix this!! Please Help me? thankyou : )