Spanish Grey Lavender Wilting in Window

I bought my Lavender two weeks ago from Richters and it's been okay since I brought it home. The taller stem has a bract with some flowers open and it likes to bend over a bit. I'm not sure why this happens but as it would straighten up again for once again no apparent reason it didn't really bother me. However I have recently made attempts to move from under the fluorescent light where it is currently located to a sunny window and both times I tried this (two different windows with different exposures) it wilted completely within 30 minutes so I moved it back to the fluorescent where it eventually perked up again a few hours later. I would really rather move it to a window. It would get more light but it doesn't seem to want to move. I've read all of the Q&As about lavender but I haven't seen another one that has a problem with moving lavender to a sunny southern exposure window.

The amount of light that your lavender gets under the fluorescent lights is way less than what it would get in a southern window in spring. And in the window, the heat from the stronger light will dry out plants more quickly.
Accustom it slowly to the higher light levels and give it enough time to grow sufficient roots to keep up with the greater loss of moisture in much higher light. Start out by shading it in the window with newspapers and only gradually remove the shading over a period of two weeks.
Correct watering is important. Water thoroughly so that water comes out of the bottom of the pot. But only water when the soil is beginning to dry. Use your finger to tell if the soil is wet or dry and water only if it is dry.