This is not self harm.
I actually take a bit of offense to that, as someone who has struggled with self harm for most of their life, in varying degrees.
Let me explain, self harm is something that the individual physically does to themselves to cause pain in order to cope. It does not have to leave a mark, contrary to popular belief, but it is physical harm done to the body.
It is possible that you have internalized what people have done to you, for example if someone would use your birthname because they were trying to hit below the belt and they knew that it would hurt worse if they used your birthname.
It is more likely that this is negative self talk, and a bit of self sabotaging behavior. Like the earlier example, you are using your birthname to make the statement more emotionally damaging to yourself. This, is something that i do also. It could be that you have the mentality that if you make yourself feel worse about the behavior you have engaged in, you will correct the problem. If you feel bad, you will in the future avoid the pain that would happen if you made the same mistake again. Unfortunately, this is not the case, making yourself feel bad about the mistake does not prevent a recurrence, it just lowers your self esteem.
P.S please do not take the beginning as me being short or upset with you, i just wanted to make sure that you knew the difference. In hindsight i think i see what you meant originally.
~Kayden