If you press the spray button whilst driving and nothing happens then don’t press it again, especially if you think the washer fluid has frozen as this can damage the whole mechanism. Since fluid expands when it freezes, you need to check for leaks once it has thawed, and repair any pipes or the reservoir tank itself. In the future, consider getting wiper fluid that has better anti-freeze technology, or pick up a bottle of 90% alcohol from the hardware store and mix it into your washer fluid to raise its freezing point.