Variable to tell the dashboard which metric to plot

Hello you all. I am using the latest Grafana release.

I have a table in Influxdb which holds a timestamp and 150 fields, each one being one metric, for instance:

timestamp metric1 metric2 metric3 …etc
11-02-21 12:11:30 3,121212 2,11111 4,932323 …etc
11-02-21 12:11:31 3,124323 2,21122 4,900886 …etc

I want to provide the user the option to choose which metric to plot in a given dashboard. To do so I pivoted the table and converted it into the following:
timestamp1 measure value
11-02-21 12:11:30 metric1 3,121212
11-02-21 12:11:30 metric2 2,11111
11-02-21 12:11:30 metric3 4,932323
etc

So at the end I had only to create a variable with the values of the tag “Measure” and filter the queries with that.

But new requirements make the pivoting not feasible (it multiplies the data heavily up to 2.500 Million rows), so I need the same functionality but keeping the original table structure, with one column per metric.

Is that possible in Grafana? Can I build a variable that hold all metric names so later I can filter by them in a query?

Thanks in advance!!