All men have sinned, so yes you are a sinner and so am I. Sin is defined as the things we do to separate ourselves from God and clearly with your narrative that is exactly what you intend, but most of us sin with far less intent but rather by pursuing our own selfish desires.

It is true that God knew that when He allowed humans to choose between right and wrong, that their natures would cause them to sin. If you are a parent, you know that if you want your children to grow up, that they are going to have to make mistakes.

Knowing that God sent his Son to die on a cross, so to the extent we commit sin, Jesus provides us all a means to become Holy again.

And yes, you can curse God, insult Him, and He still loves you and offers you the chance for reconciliation and redemption and all you have to do is want it.