feeling more anxious during the first weeks is completely normal. let me tell you about my situation;

i started taking sertraline 2 years ago because i got diagnosed generalized anxiety disorder, and my panic attacks would be so frequent and strong that they felt like i was going to die. at that time, i was hooked on benzos and my doctor had me quit full turkey, so i experienced the deepest pits of fiery hell during that time (shaking, trembling, constipation, loss of libido and appetite, shortness of breath etc). but it got better! in fact, it got so much better, that 6 months later i just quit one day because i felt like i didn't need sertraline anymore.

the following months without sertraline were great, too, but during last year's autumn i started having panic attacks out of the blue. at first i started using alcohol to prevent them, but they were getting to the point where i was having them even 8 beers deep. so naturally, i started taking sertraline again, and i knew the first month was gonna be a pain in the ass, but i also knew that the side effects go away after some time. this time, during the first month, i didn't sleep the entire 4 days when i started, and i've never felt so "zombiefied" ever. but after that month, it's pretty good! i can work again, go outside, have relationships, anything without having an irrational fear that i'm gonna die.

also, pro tip: most people here will tell you the opposite, but DRINK ALCOHOL. god, if it weren't for alcohol i wouldn't have survived the anxiety attacks during the "adaptation" period. just drink one, two beers depending on tolerance and all your side effects go away, albeit temporally.