Help us get a wheelchair accessible van

I really do not want to do this but its the only option i have. My son Adrian is 8 years old and has Athetoid Cerebral Palsy, Epilepsy, Chromosomal Abnormality, an unknown genetic disorder (possibly a rare genetic disorder called Angelman Syndrome) among a few other things. He is 70 lbs and i about cant lift him anymore. He is getting to big for the  back seat of my little car and i also have 3 other kids to haul around and im a stay at home mom because i have no help with him. I really need a wheelchair van but will never be able to afford it with how expensive they are. Anyone that knows me knows i would NEVER ask for help if i didnt need it. If i cant raise enough to get a van already equiped i would like to at least get a bigger vehicle (van) for him which i plan to do this tax time and maybe can have it modified. I really need a vehicle where i can just push him up into it in his wheechair and strap him down. He passes out when i move him due to seizures or maybe a underlying issue we aint found yet so he will really benefit from this. Any and all help is greatly appreciated and if you cant donate just pray for him. Thank you!