I had a friend in Navy dep who I hungout alot with. He shiped before me.?

I didn't write him 1 letter. I feel like a total . But I didn't do it because he wanted us to get stationed in the same place and he got into trouble and was told he couldn't leave the country and I wanted to get stationed abroad, I really want to go to Yokuska Japan. Now I just feel like such a sbag. What are some good meaningful thing's I could do to make it up to him? Or is the friendship on the scrap heap?