The American Public Transportation Assistance website has a link to organizations in Indiana that offer public transportation for the disabled. This includes C.A.R.T. and other modes of transportation.
Indiana Links for Transprotation
Another alternative would be to place an ad in your local paper asking for a retired person or someone in your community to work as an assistant and provide rides when you need one.
I don't know if you are a member of a church or a civic organization or not but you can usually find lots of support there.
Please take a look and let me know if you need more information.