Imagine there is a bomb in the room and you are trying to find an exit how to escape. We would try our best. Similarly we should chant our rounds in the same spirit that Maya is ready to attack, so we must try our best to surrender to Krishna.
Actually 16 rounds is nothing. Chaitanya Mahaprabhu said 64 rounds.
Initiation is a kind of registration.The main thing is how sincere, serious, dedicated and honest you are. If you are committed to Sri Guru & Vaishnavas, then you will surely progress in spiritual life.
Chant just like a child. When a child cries, then father-mother may give the child some chocolate, biscuit. If the child is still unhappy, they may give toy. But if still crying, then the mother takes the child to her lap. Then the child is pacified. We have to cry for God like that. From the core of our heart, we have to chant like that. Do we chant like that?
Subtle effects the gross. Subtle body has to be changed by listening hari-katha.
If we listen hari-katha with love & devotion, it can cleanse our heart from anarthas.