God knew about that tattoo before you ever got it.
He knew about this struggle before you ever had it.
He knew about this question before you ever asked it.
And His promise was made to you, and is waiting to be fulfilled in the space of time, before you ever accepted that He loves you.
The tattoo is meaningless, because it represents nothing real. It is not a spiritual conflict that the tattoo brings. It is a sense of guilt for something you have already been forgiven for. God didn't accept you, forgive you, and then decide to punish you for what you have been forgiven for. He doesn't beat His children.
Do what you like with the tattoo. Keep it, cover it, alter it, as prayer directs you to do. Nobody here is qualified to give that advice. But don't make an issue out of it that God is not making out of it. That isn't coming from Him at all. That is internal, destructive, and wall building from the relationship He wants with you.