Transmission issue

Hello and welcome to 2CarPros. In my experience, flushing and changing the fluid at that high mileage will ruin your clutches in a matter of weeks. This is because the parts are pretty worn, and flushing and changing the fluid will increase the pressure being put on them. Instead. I would suggest check the fluid level and then add as needed. If that doesn't fix it. Then drive patiently and slowly until you have the money together to repair or replace it. I'm attaching Alldata's information on how to check the fluid and add in the images. I hope that this information helps.