I am coming onto Sertraline at the moment, having switched from Citalopram, which stopped working for me.
The side-effects have been shocking, but what I have read suggests they subside after about two weeks (not long for me). Certainly for me I am sleeping again without tablets, and the anxiety is not as bad as it has been.
I take my 50mg tablet in the morning, and get a spike of anxiety after a couple of hours. This builds until about 2000, when it begins to subside again by bedtime. I wake up with no anxiety!
It seems that while your body is stabilising, the time you take it will matter, but later on it won't as much, as the half-life means you will sufficient residual in your body.
I found that Citalopram was good for alleviating my anxiety, but I was not myself, I was dulled and clumsy in my brain, and made alot of mistakes. Already on Sertraline I feel sharper and more with it.
Some useful views from users here, which I am still finding helpful:
https://www.drugs.com/comments/sertr...ty-stress.html
So, maybe change when you take it, and keep the faith- it will get better!
And see if you can get an emergency apppointment!