Thank you for writing. For your father to involve you in his fight with your mother is very, very unfair. You cannot and should not be his confessor, his therapist, or his ally against your mom. His fight with your mom is his fight with your mom.
My guess is that there is more to your parent’s divorce than your father is willing to admit or understand. Your mom didn’t “take his money”. A court of law awarded it to her. You don’t need to know why. It’s enough to know that there are generally two sides to the break down of a marriage. The court already dealt with that. You don’t need to.
Children of divorce can and do love both parents. You are not required to take sides. Often parents who were not good for each other are still loving and capable parents. Just because they can’t get along with each other does not mean that they can’t have a good relationship with you.
You cannot single handedly manage the stress of trying to “hold everyone up”. IT’s not your job!! I hope there are people in the extended family that you can look to for some support and help. Turn the care of your dad over to relatives or adult friends you trust. Your school counselor may be able to help you find a therapist to provide you with some support and some practical help. Often a therapist will ask parents to come in, either together or separately, to work on getting kids like you out of the middle.
I support you in refusing to talk to either parent about the other. Politely decline to comment if either bring it up. Remind them that you love them both. Change the subject. Respectfully withdraw from the conversation or leave the room. Reassure you dad that you do love him but loving him does not require that you hate your mom.
I wish you well.