We hear your frustration and we understand why you feel overlooked and even angry in your own home. What you describe is not really about water alone, but about consideration, stewardship, and respect for others in the household. You are right to desire fairness and to want everyone to have what they need. Scripture calls us to look not only to our own needs but also to the needs of others, as it says in Philippians 2:4 each of you not just looking to his own things, but each of you also to the things of others. And in Romans 12:10 we are told to be devoted to one another in brotherly love, giving preference to one another in honor. When one person consumes the majority of a shared provision without contributing or considering the rest of the family, that does not reflect that love.
At the same time we want to gently correct a few things we noticed in how this conflict is being carried in your heart and in your words. Even when we feel justified, God calls us to guard our speech and our anger. You referred to your brother in a contemptuous way and wished that your other brother would shut up for good. That kind of language, though understandable when you are irritated, does not build up and can harden bitterness in your heart. Ephesians 4:29 says let no corrupt speech proceed out of your mouth, but only what is good for building up as the need may be, that it may give grace to those who hear. And Ephesians 4:26 says be angry, and don't sin. Don't let the sun go down on your wrath. James 1:19 reminds us to be swift to hear, slow to speak, and slow to anger, for the anger of man doesn't produce the righteousness of God as seen in James 1:20.
We also want to encourage you regarding your mother. Even when you disagree with her decision, God still calls you to honor her. Exodus 20:12 says honor your father and your mother, that your days may be long in the land which Yahweh your God gives you. Proverbs 15:1 says a gentle answer turns away wrath, but a harsh word stirs up anger. Your mother is carrying the burden of providing and managing the home, and while you see her as enabling your brother, arguing in a way that dishonors her will not bring peace. Romans 12:18 says if it is possible, as much as it is up to you, be at peace with all men. That means pursuing peace even when you feel unheard.
Your concern that your almost thirty year old brother is living at home without helping is a valid biblical concern. Scripture teaches that a man should provide for his own and not be idle. 1 Timothy 5:8 says but if anyone doesn't provide for his own, and especially his own household, he has denied the faith, and is worse than an unbeliever. And 2 Thessalonians 3:10 says if anyone is not willing to work, neither let him eat. It is not unloving to expect an adult living in the home to contribute, whether by buying his own provision if he has unusual needs or by helping pay for what the family shares. Your suggestion that he buy his own pack if he needs that much water is reasonable and considerate for everyone, and your mother's suggestion that he at least help pay toward it is a step in that direction.
Regarding moving out, the desire for independence is not wrong, but we encourage you not to make that decision solely out of anger or in the heat of this argument. Proverbs 21:5 says the plans of the diligent surely lead to profit; and everyone who is hasty surely rushes to poverty. If the Lord leads you to move out, do so with planning, wisdom, counsel, and provision, and not as an escape from unresolved conflict. It can be good to save and prepare quietly while you continue to honor those in your household.
We also noticed your request did not mention Jesus Christ, and we want to gently remind you that it is only through Him that we have access to God and peace that passes understanding. John 14:6 says Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me. And Acts 4:12 says there is salvation in no one else, for there is no other name under heaven that is given among men, by which we must be saved. If you have not already, we encourage you to put your trust in Jesus, confess your sins, believe that He died and rose again, and follow Him. Romans 10:9 says that if you will confess with your mouth that Jesus is Lord, and believe in your heart that God raised him from the dead, you will be saved. It is through Him that we can find grace to forgive, to speak gently, and to be peacemakers.
We pray together for you now.
Father in heaven, we come before You in the name of Jesus Christ and lift up this dear one and their whole family to You. Lord, You see the tension in this home, the frustration over provision, the feeling of being unheard, and the anger that has built up. We ask You to pour out Your peace upon this household. Help this one to speak truth with gentleness and respect, to honor their mother even in disagreement, and to release bitterness and harsh words toward their brothers. Convict the older brother where he is being inconsiderate and idle, and move him to take responsibility and contribute honorably to the home. Give the mother wisdom to lead the home with fairness and discernment and not to show partiality. Teach each of them to prefer one another in love and to bear with one another in patience. If it is Your will for this one to move toward independence, provide clear direction, open doors, and the resources and wisdom to do so in a way that honors You. Above all, draw each heart closer to Jesus, that this family may be reconciled first to You and then to one another. We ask for forgiveness where there has been sin in word or attitude, and we thank You for Your mercy and grace to make all things new. In Jesus name we pray, amen.
We encourage you to go to your mother and your brother when you are calm, not to accuse but to share your concern with humility. Propose a clear and respectful solution, such as each person contributing or your brother keeping his own supply if his work requires so much water. Continue to pray for them, bless them even when it is difficult, and trust that God sees your effort to do what is right.