Basically, fear of losing my family can be thought of as being a fear of being rejected.
It also induces a fear of being hurt by them.
And a fear of being alone.
Because they're all part of the same basic fear, that I think a lot of humans have. Humans basically seek companionship; we're essentially hard-wired to want it. And my true fear is of not having it. In short,
I fear doing a lot of things because I am afraid of rejection (because that would hurt, something I am afraid of), and my fear of rejection is because of my fear of being alone.
...Still working on how "fear of being hit by a fast-moving ball" fits into the picture, though!