New and need perspective on how to make a mental shift

[Valerie Preston]

My name is Valerie and I'm in DFW.  My husband and I (both 60yo) have two properties (our primary residence and a long-term rental).  Each is valued around 500k and we owe a total of less than 100k between the two.  Being raised by a single mom living paycheck to paycheck, I've got this mental block when it comes to debt.  I know I should be leveraging the equity in both of these properties to purchase more investment properties, but I'm having trouble pulling the trigger.  What advice / books/ resources would you recommend to help me get over this mental hurdle?