The spray foam will fill every cavity and gap on your metal shed walls ceiling and under your floor.
Paint to stop condensation on metal roof.
The best way to stop condensation in a metal shed is to apply closed cell polyurethane spray foam.
The material literally traps and holds the moisture resulting from condensation.
When conditions change the ambient air temperature usually rises thereby raising the dew point.
Once sealed moist air will not be able to contact shed surfaces allowing it to escape instead of condensing on walls and ceilings.
The answer is a product called dr pstop which is a felt like material with a rubber backer that can be applied to the back side of metal panels that will trap the moisture as the condensation forms.