Actually mercury is in the sign of exaltation of the sun, triplicity and face of sun. So on his side, he does still have feelings for you.
However, he is retrograde, backing away from his previous feelings.
With moon VOC you shouldn't expect anything to change in the situation for the time being.
His wife, the 9th house, has angry mars on the cusp opposing him, so her influence is quite strong on your brother. Consider also that he is in her house, strongly under her influence.
It's always sad when there is strife like this in a family, and the chart clearly shows your 4th ruler of the home and family ruled by Venus in detriment and approaching a conjunction with Chiron, the wounded healer.
You on the other hand are about to square pluto, near the 7th house cusp.
Entering the type of power play you are planning might not be to your benefit. It could turn against you.
Sun also represents your 2nd house of money, so the agression of this pluto square will also influence your finances.
Sun in the sign of money, taurus, shows you putting perhaps too much value on the issue of money, pushing too much.
Taurus is ruled by Venus, so you are doing all this in the name of your family.
Your brother separates from Venus, he is leaving your family, bur heads toward North Node, he is following his own path. He must in reality find his own destiny. Interestingly, that same Venus rules his 2nd house of money, so for him it is not so much getting the money per se, as showing his independence from the family. He is trying to become a man. And probably being goaded into this by his wife. Moon's last aspect was an opposition to Neptune, her ruler. He goes along with it because she is his wife, not because he would do it on his own.
So, it would help you to try to loosen up your approach to him somewhat, recognise him as an inividual, aires, and use the positive energy of pluto to rise above the situation, like the phoenix.
The sun that represents you is in the 10th house, where you are worried about your reputation. You are admittedly in a frustrating situation.
But remember you are Leo, the strong lion, generous and benign. Talk to him from your heart.
Look towards healing, rather than winning. Work towards the values of family and unity.