What you need to understand in your grumpy self is that you need to stop being like that and be saved from it by Christ.
That is the only way to change!
In your grumpy self, where you are bitter, angry, resentful, envious, etc draw in the presence of the Lord, and let His loving truth guide you from there, to dying to being like that, and coming to newness of life instead.
i struggled with sin all my life before i realised that in my sinful selves i needed to be saved, not think i was saved because i believed in the Lord at other times.
You have to make Jesus your Hero in ALL of your life. He will become that if you let Him change you from being the bitter resentful person you have become to becoming loving, thankful, joyful and supportive of other people going through a hard time.
In repentance lays your chance for change. Letting go of the right to be who you have become - e.g laying down your life for Christ, dying to the old nature, and coming to life in the new.
Peace.
Colossians 3:1-17
Since, then, you have been raised with Christ, set your hearts on things above, where Christ is, seated at the right hand of God. Set your minds on things above, not on earthly things. For you died, and your life is now hidden with Christ in God. When Christ, who is your life, appears, then you also will appear with him in glory.
Put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry. Because of these, the wrath of God is coming. You used to walk in these ways, in the life you once lived. But now you must also rid yourselves of all such things as these: anger, rage, malice, slander, and filthy language from your lips. Do not lie to each other, since you have taken off your old self with its practices and have put on the new self, which is being renewed in knowledge in the image of its Creator. Here there is no Gentile or Jew, circumcised or uncircumcised, barbarian, Scythian, slave or free, but Christ is all, and is in all.
Therefore, as God’s chosen people, holy and dearly loved, clothe yourselves with compassion, kindness, humility, gentleness and patience. Bear with each other and forgive one another if any of you has a grievance against someone. Forgive as the Lord forgave you. And over all these virtues put on love, which binds them all together in perfect unity.
Let the peace of Christ rule in your hearts, since as members of one body you were called to peace. And be thankful. Let the message of Christ dwell among you richly as you teach and admonish one another with all wisdom through psalms, hymns, and songs from the Spirit, singing to God with gratitude in your hearts. And whatever you do, whether in word or deed, do it all in the name of the Lord Jesus, giving thanks to God the Father through him.