My personal opinion is that this is an emotional restoration dream. You are a bit concerned about your father (cancer and being unsaved). A jacket represents spiritual preparedness, in this case, being prepared to possess a special word from God. A gun, in a positive sense, may speak of a special word of God that can be shot (with a special golden or blue or purple or silver bullet) right into the heart of a person, with the aim to change his heart. The fact that it was a fake gun speaks of you not yet possessing the gun (a special word from God).
Windows speaks of special revelation knowledge. We “see” through a window and that speaks of spiritual “insight”. In the dream, the windows are exactly like the fake gun. The windows are broken so the “special insight” is not really there. You do not possess the spiritual insight about or for your father yet. You understand that it needs to be repaired first before you will receive special insight.
The laundry all over (the bathroom and even the bath) speaks of your father’s bad preparation for life. It probably needs washing and ironing, which speaks of him not spiritually prepared for life and for heaven (salvation).
The car speaks of your motivation or your quest regarding this matter (the matter of helping your dad as you have explained). He thought it was because of sinful things (dirt, probably his sinful acts) but you knew it was just because of the broken windows that need repair first (spiritual insight).
“The cost per hour, the cost per meter the cost per item”, part speaks of your understanding that you need to pay a price to be successful. That price is “faith”. The heavenly currency that we need to pay for spiritual blessings (in this case the revelation knowledge or spiritual insight or the gun with the silver bullet (silver – word to cause repentance) that you need to shoot into his heart, take faith to obtain.
So this is either an emotional restoration dream or/and a message of God to inform you that you need to have faith for that special word. If you have faith, He will give it to you so that you can go and help your father.