All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The dowry is the right of the wife and if she wants to totally or partly renounce it, she may do so if she is legally capable to dispose of the money, like if she is adult and of a sound mind.
Therefore, you may renounce any portion of the dowry that you wish from your husband and what you did is a permissible way of renouncing it.
Allaah Knows best.