The 7 of Cups is about making a choice between different ideals. But Cups, with the water element, don't like making definitive choices that much, making this 7 in this suit a bit of a hard choice.
Listen only to yourself as you make the choice of what ideal to pursue. You might even want to ignore the advice of those around you for this choice, as it is you who has to do the work to get there.
You've overcome many illusions so far already. But you might be tempted to believe in one of those illusions again. Try to believe in something that's attainable this time.
When this card falls in an upside down way, you are probably too stuck in evaluating things. At least fulfill your existing commitments.