Too many Doms fall into this trap including me at one time. Being a Dom does mean to help mould the sub into that which she wants to be. If the Dom is smart he knows when to praise and that it is needed a lot more often then is fault finding and lectures.

You are giving him a gift that is too be treasured. You do need to talk with him just do it in a very respectful manner. Let him know how this hurts you and how it will kill your sub if it continues.

That last part comes from experience