The U.S. made a promise to protect Ukraine; has the U.S. abandoned that promise?

Matthew in Ukraine has already survived being shot and has now survived both a missile strike on his favorite cafe and a drone attack on his vehicle. The Russian invaders know his unit exists and where they are operating and are very actively trying to kill him. How is he coping? What has changed? And what does he want Americans to understand about Ukraine at this point in the conflict?