Relationships are give-and-take, and when you're a tennis player, you're certainly not giving. You have to be self-absorbed. It has to be about you.
Hard though it may be to accept, remember that guilt is sometimes a friendly internal voice reminding you that you're messing up.
Modeling is a lonely business... You don't speak. You don't really portray anything but an image... the business is so superfluous about dealing with the outside, it messes with your mind.