When a woman is doing her best for you then you should appreciate her, and realize that she is trying her hardest no matter what the outcome is. Some men get upset because something does not turn out the way they expected or the outcome is not what they hoped for, and they turn on the woman who is their partner and the one rooting for them. If you have someone who really cares and who tries their hardest then you should be appreciative for the effort that they expended even if the outcome is not what you were hoping for. If you can't appreciate the fact that she tried then you do not deserve someone who is always in your corner cheering you on and being your biggest advocate.
Too many men take the woman that loves them for granted, assuming that she will always be there standing behind them and working hard on their behalf If you do not show her that you appreciate all that she does and how hard she tries then eventually someone else will appreciate her and you will lose her for good. No one wants to be a door mat or a whipping post for someone who does not show that they value the hard work and effort put in, and if you do not appreciate what you have and you do not deserve her then you could wake up one morning to find someone who does appreciate her and shows it has stolen her away.