ScarletPimpernel, you can survive something like this because, in the grand scheme if things, this is not a life or death situation.

It was a mis-connection.

It feels massive because the mis-connection occurred when you really needed a connection to be made. For whatever reason, it wasn't, even though you expected and needed it to be. But, on this one occasion out of all the many occasions, the connection failed.

The connection failed on this occasion. It has likely failed before, and may fail again sometime in the future. But most of the time your connection is good-enough, and you receive what you need, more or less.

You will connect again.
You will mis-connect again.

Even though you two mis-connected this time, you survived it. You got through. It would have been so much better /easier/safer if you had been able to get what you needed at the time that you needed it but, thankfully, you got through it.

How do you survive something like this? You remember all the times you did manage to connect, let the triggered feelings subside, wait for the emotional storm to pass, and then you connect again.