No, do not flip it. Import it as is and then stack it. You should then have three columns: the treatment (nominal modeling type), the time point (initially nominal, but should be changed to continuous), and the observation (continuous). There will be three rows for each treatment and time point (tall format).
You can use the Graph Builder to plot the mean value. Drag the time point to the X axis, the response to the Y axis, and the treatment to the Overlay role. That set up should be a good start. Explore the properties on the left side for each graphing element.