Hi, there and welcome to the BB.Glad you were at the SLC symposium. I was there as well and the program was quite good this year with all the new research going on.
I've never heard anyone else connect/blame botox for depression to be honest! My only comment would be that perhaps w/in 24 hours of an injection, it "hits you" once again that you have SD and how tough it can be. Perhaps within 48 hours your voice is starting to improve and so you "get over" that lousy feeling, realizing the improvement.
Of course, you can come back and say that it's not related to your voice improvement if the timing varies, but I'd say with certaintly there's no connection to the botox itself.
It's also possible that you can create a self-fulfilling prophecy where you expect yourself to become depressed within 24 hours and now take it as a time to reflect on why SD is so rough with each injection?
And I'm not here to give medical advice, but unless you're experiencing pain for whatever reason after Botox, I'm not sure I'd take Advil just for the heck of it. But the fact that you said you "read about" the flu-like symptoms and perhaps anticipate them as a result would be a similar reaction to your Botox shot w/in 24 hours.... try not to walk around expecting the worst! I have never had flu symptoms after Botox and most of the people I know never have either.
SD can be tough so perhaps a going through the treatment is putting a lot of stress on you even though it helps. I doubt it is the Botox itself! If any symptom were related to Botox, symptoms wouldn't abate w/in another 24 hours as the Botox is clearly still in your system.
I'd try to relax after your injections and maybe even take some time by yourself to chill out over having the disorder. It can be rough but it's very treatable these days and can be managed quite well. As you noticed in SLC, being in touch w/ other SD-ers can help as well.
I'll be the first to admit that SD sucks but try to make the best of it even when the treatment gets you down. At least it works!
Good luck,
Laurie