Is the only option to have it professionally measured? Is it possible to measure on your own and order that? Is it possible to have it professionally measured but then install yourself?

Yes, it is possible to measure and install our products on your own. We do have measuring guides and installation instructions located on Levolor.com. For questions on the measure/installation services offered by the store, please reach out to your local Lowe's retailer for details. - Kimberly