Leaping, I know what you are going through, this has happened to me too. I HATE how they quack suicide and when we show them attention they learn that this is a good way to get us involved again. SO MANIPULATIVE. Keep working your recovery though and hopefully that will allow you to get to a point where you have no urge to respond to (or even read) his texts.
If you really think about it, he is in a different state and you can't run and help him anyway, which is GREAT. If there is any real problem he has his mom and brother there and they can deal with the problem if they actually see one and if they choose to.