Help me keep my house

Hi! I honestly just need some help to buy my ex out of the house we both own. We split this last December and have a special needs 8 year old child. He is insistent that he is going to sell it if i don’t buy him out. This house is less than 5 minutes from my childs school and this school fits all the needs that she needs to succeed. My ex knows that if he sells it that it will force my child out of the school she is doing so well in but he doesn’t seem to care about that. I do. The only reason i want to buy him out is so that the kiddo can stay at her school. I know it’s a lot of money I’m asking for but anything will help! Thank you for taking the time to read this and maybe help.