Unexplained credit score drop

I habe zero debt, a think file with three marks from years ago, 5 attempts to aquire a credit cards also from some time ago. Recently opened to loans one for my work truck, and another for my wife and baby to have when I'm working. Well this was an attempt to raise my credit rapidly. I've made all my payments on time and in the beginning my score was jumping, ( started 520 or so peaked at 596 or so) suddenly my credit dip 18 points an i can't and reason as to why?

posted