i cant set a mesh/actor var in a struct, either in the editor panel of the struct, or in a BP (rather do it in editor panel)

You made common novice mistake, blueprints are not objects, they are classes same as c++ classes, they wont exist until you spawn it from class. Open class viewer and search for your blueprint there, it will open your eyes Object type (blue color) can only hold already instatiated object, outside o…