The ego uses affirmation to try to implement, establish, build, attain, increase, add, supply or otherwise bring about something which it believes does not exist yet.
The problem with that is that everything it tries to invent is not necessary, because you have no real needs, being already perfect.
Acceptance of what is already perfect about you is a far better strategy. God is the one who has created perfection. You don't need to create yourself, redefine yourself, rebuild yourself, or fill a void. You only need recognize and accept what is already true.
God has already done, what the ego is trying to do. God already created. Now the ego is trying to make stuff. Making stuff, affirming trying, trying to be convinced of stuff, and using affirmation as a defensive weapon to counteract other ego stuff, is pointless.
What I like to do now, is to move towards acceptance "through" a kind of affirmation. Not an affirmation which "makes firm", but more of an acknowledgement. For example, "I am as God created me". It is not an affirmation because it does not "make you be" as God created you. You already are that. But it acknowledges that this is already true and accepts it, rather than it being something you are doing for the first time.
God already gave. God already created. God already shared perfection. God already provided wholeness and health. We were the ones who tried to reject it and deny it and throw it away. We are simply reclaiming our inheritance. Accepting atonement is simply accepting that everything is STILL as God created it and nothing else has happened.