Save my knees

I dont really like to ask for help. My nephew suggested i try this since everything is getting harder for me. I have ostioartrotis and my knees are getting worse and also have a crooked vertabrae. I was told by drs to walk the minimum possible since i can not get an operation til i am 65 and i am 46. I have two small kids and have to walk them back and forth to school. I go six times a day and each walk is 45 minutes. It is too much and i am in extrem pain all day long. I need to get transportation to be able to take them to school and not be putting so much weight on my knees or i will end up in a wheelchair long before the operation can be done. Please help us get a car to help me save my knees from futher detiriation. Thank you and God bless each one of you!!!!