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The sudden shriveling of leaves, especially if there are no spots or discolorations on the leaves, suggests some kind of bug (probably very tiny, since you don't see it,) like thrips or aphids. Or something could be eating the roots. Here's a discussion of the most common wisteria problems: https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-diseases.htm
Probably the best idea would be for you to have some samples of leaf and root analyzed. You can call the nearest botanical garden for information about contacting a master gardener group, who will help you with analysis and treatment. Or you might be able to find advice through a nearby university, nursery, or plant store.

A flower's fragrance decreases once the flower is fertilized or pollinated which allows flowers that have yet to be pollinated to be more attractive to pollinators. So maybe this is what happened to your wisteria.

Yes, wisteria would work on a pergola with some training of the vines. However, wisteria needs plenty of sunlight. It will grow in partial shade, but needs at least 6-8 hours of full sun to bloom best.

If the wisteria is not good for your location based on its sunlight criteria, then you could consider star jasmine (which is a shade loving vine) and Vitis Vinifera (semi-shade or no shade). Here is an article with other good choices for a pergola:

https://www.gardeningknowhow.com/special/spaces/pergola-climbing-plants.htm

For more information on growing wisteria, please visit the following link:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/growing-wisteria-proper-wisteria-vine-care.htm

Was your wisteria bought at the nursery or grown from seed? Wisteria grown from seed can take up to 15 years to bloom, as incredulous as that sounds.

The following article details the reasons for non-blooming wisteria and offers suggestions to remedy it:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-blooming-problems.htm

Does the wisteria develop buds that just aren't opening? If so, this article will help you:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-blooming-problems.htm

I have read that you can punch a few holes in the plastic for ventilation and that you can even place your wisteria cutting in a lightly shaded sheltered location.

For more information on propagating wisteria from cuttings, please visit the following link:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/propagating-wisteria-cuttings.htm

There may be a delay in your wisteria leafing out due to the weather, so it may just be dormant. In order to know if it's dormant or dead, you should check a stem for flexibility. If the plant bends easily, it’s ok. Dead plant stems will snap and break off. Also, conduct a scratch test. Scrape off a little bark - do you see green underneath? Green indicates health. Unfortunately, if it’s brown and dried out, the plant is most likely dead. For more information on the above information, please visit the following link:

https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-no-leaves.htm

If your wisteria is in fact dead, it may be due to a cold injury it sustained over the winter months.