Need help with celtic cross tattoo (pics)

I got this tattoo when I was 18: 5 years later I added the following to the outside and inside (lines): I need help trying to decide what I want to do next with this mess. I should not have added the lines to it, but the artist said he would clean them up for free since they are uneven. If anyone has advice or can even help me design a new addition for it, please do so! I'm open to all ideas. Thanks in advance.