Mobility van with wheelchair lift

Hello,  I am a single mom of three wonderful children.  My youngest is in a wheelchair because he has Cerbral Palsy, seizures, and mentally delayed.  I am a teacher in a district that is rural and one of the lowest paid in Arizona.  I love my job and touching the lives of so many students and helping them to learn to love science.  I am only able to barely pay basic bills and there is no way to afford a wheelchair vehicle.  My son now weighs 155 pounds and his wheelchair weighs 60 pounds.  I lift him in and out of the van every day.  He is unable to walk without a lot of help.  He goes to high school next year and will only grow more as teenage boys do.  Please, help if you can.  Thank you ahead of time!!!