3 Years in the garden has yet to bloom.
Cornus Kousa Wolf Eyes
Certified GKH Gardening Expert
I would start with a soil test. This is the best way to determine if too much nitrogen is the issue or what you can do to amend the soil for the best blooming outcome for your tree.
Your nearest County Extension Office can help you with a soil test for a small fee.
These links will help you locate the nearest extension office and review the care requirements for your Dogwood Tree.