Replace period with Comma and lowercase next word

I have what would seem to be a simple edit entry I want to make but it's not working for me. When editing AI, I frequently need to delete a period after a word, insert a comma instead and then lower case the next word.

An example:
"And I was angry. But I still didn't"

I want it to say:
"And I was angry, but I still didn't"

For some reason what I have keeps copying the word "angry" and inserting it and not making the next word lowercase. Can someone please help with this?

Here's what I had. My cursor would be right before "angry".
{Ctrl Right}{Delete},{Ctrl Right}{LowerCase}{NoSpacing}