Whether the feelings are an accurate relfection of reality or not, these feelings are common. It could be your spouse, failing to see all that you do for them, or it could be children, colleagues, and friends.
Know this though: You don't appreciate God as much as He should be appreciated. You don't know His incredible holiness, how much he has blessed you, or the suffering that He bore on the cross for sin.
Allow your unrewarded servitude for others to draw you closer to Jesus. Know that he is the only one who has the right to complain in this, and that he doesn't.
Know also that if you suffer in this for Christ, you will be comforted.