For a Lab issue like the one you ran into, the options available to you for now are either to create a new lab (using the ARM template that was used to create the previous lab) or to reach out to support to see if we can restore the lab from our end. There is currently no functionality that will allow you restore the entire lab to a previous state (but if this is a feature you would like to see implemented, we would love to hear your feedback on our user voice fourm).
If someone was to run into a VM issue, there are a number of options depending on what went wrong which commonly include restoring the VM to a recent state using a latest snapshot/custom image.