I used to pray like this in college. I didn’t tell God about the things my heart truly desired because I felt I didn’t deserve any gifts from Him; my sins seemed too much for Him to look past. Looking back, I now realize I was speaking to God the same way I tend to talk to acquaintances; I put up boundaries in order to avoid discussing the aspects of my life that are not so great.
I felt guilty about the walls I had created between myself and God, which in turn made my prayers shorter and less frequent. I was avoiding Him. I knew HE knew I was not living my life the way He wanted me to be, and the thought of REALLY talking to Him gave me overwhelming feelings of guilt and anxiety. Perhaps you can relate.