Wow. What a weird thing for your aunt to do. She left her niece more money than she left her own children?
That is a strange thing to do.
If I were you, I would value the feelings of the living more, and not delude yourself that you are holding on the money to "honour your aunts wishes".
Perhaps your cousins have behaved badly, but I can understand why they have behaved badly. They have suffered a hurtful rejection and betrayal by their mother.
it is probably important for them to feel that reasonable people know that what she did was unfair and bound to cause hurt, resentment and fighting.
If I were you, I would call a summit with your cousins and say that you are sorry that you have been used as some kind of tool in your aunt's sorcery, but that your relationships with your living relatives are far more important to you.
Tell your cousins that you would love to see a line drawn under this now. Divide the money equally and hope that they accept them. Don't expect them to be grateful though. That money, should, in a perfect world of sane mothers, have been theirs anyway.
I don't know how close you are to your cousins, maybe not that close, but do the right thing. Otherwise, for the rest of your life, long after you have forgotten what you spent the money on, it will be there, picking and niggling away at your conscience like a half-healed scab.
My Dad had half-brothers and half-sisters and whole siblings, and I know a little bit about what I'm talking about. My Dad is the only one who is on speaking terms with everybody. He is the only one that valued that state of affairs over his personal tranche of the money. An amount that seems more and more pathetic with every passing year.