So this girl was a total bitch who cared more about social status at her high school than getting along with her dad who was apparently trying to raise her by himself while being deaf and mostly mute.
She tries to commit Self Delete on her birthday because she's all emo HOW COULD THIS HAPPEN TO MEEEEEEEEEE
Then the dad takes her to the hospital and they transfuse his blood into her and she lives.
It's not clear that the father has actually died or is just weak and sleeping it's unrealistic to expect a hospital to endanger a healthy man's life to maybe save someone with a severe gunshot wound, but there's a definite implication from the flatlined heart monitor that someone died. The whole thing makes no sense.
The daughter wakes up and is sad because she has failed to kill herself and who does she see the moment she wakes up, that loving dad that makes her so miserable in the first place.
Then the video says to appreciate your loved ones or something.
Presumably based on the sappy music we're supposed to think the girl has woken up with a revelation about how much the dad cared about her, but if it wasn't evident already then she wouldn't figure it out waking up in the hospital, so I think my interpretation makes more sense.
No, the video was not very sad. The dad's situation of having an unappreciative suicidal daughter is tragic, but it's offset by the fact that he's a supporting role and the daughter is really the lead character of the piece, and she's a total bitch.
edited for typos