Hi, Prairierose,
And welcome to SR's MH forum!
I suffer from SAD, but, it's the boring ole wintertime kind! :rof
I was unaware of a summertime SAD until you wrote. I just google'd it and am amazed at the literature! Here's a good piece with some people's experiences that you may find helpful, though. It's from the NY Times.
Seasonal Depression Can Accompany Summer Sun - New York Times
Others will be by and may have some personal ESH, (experience, strength and hope), to share with you.
I look forward to getting to know you as we both go on this journey.
Shalom!