You scored decreased mainly because power prep 2 is difficult than pp1. The quant section of pp1 is easy and its not even close to the real GRE test quant. Stop worry about the decline in the score, focus on your conceptual gaps and do more practice of real GRE questions.
One useful website I would recommend for real gre question is
Scholar Den (google it), they have free questions related to quant, with time and analytics. Do check your qs accuracy in that platform and keep me posted, I would guide you further which other resources to use.
Right now I dont see any major issue, its shows that you are unable to solve difficult and tricky qs (hard and very hard).