The sentence is this
if you know a better way for me to live through my son, I'd like to hear it.
The usual meaning, as Mick suggests, is to live the life one wants to have through close involvement in someone else’s life. It’s commonly used to talk about parents who had ambitions that didn't go as far as they wanted, and are pushing their children to achieve similar things so the parents can feel accomplished. It can also be used for any other case where one person’s desires are satisfied by making someone else achieve them.