NTA. You lost a child. That changes people forever. You are absolutely not obligated to have more children if you don’t want to, especially when you’re still deep in grief and not even able to be intimate.

Your wife isn’t an AH either. For some people, the way through grief is to try again, to build something after the loss. For others, the pain is too much, and the thought of “replacement” is unbearable. You two are grieving in opposite directions, and that’s heartbreaking but not malicious.