I have a slippery L5, when it bothers me I use Kinesio tape - helps to stabilize things-
Knesio tape - Google Search

You might need a PT or chiro that uses it to apply it the first few times for you.. I've used it for my shoulder, elbow, ankle...this last year as needed..

Or family/friend can watch some you tube videos on how to apply and help you do it. Low cost and worth a try..

A MRI might be the next step due to the pain & symptoms...