Hi Hopeful! Welcome to the forum.
I was on Lexapro (10mg) for a month when my anxiety first surfaced. I felt no anxiety on it, but I slept for 13 hours a day, became some kind of drug-induced narcoleptic, and couldn't stop eating. I went off it because I couldn't function like that in college.
Last fall, I started on sertraline (generic Zoloft) and felt positive effects within the first week of being on only 25 mgs. I yawned a lot and it felt like bugs were crawling across my brainstem every time I yawned, but my brain felt better and I felt hopeful. The side effects didn't fully go away for months until I was fully used to being on a full dose of 50mg and taking it in the morning rather than at night. Even now I can feel a sort of weird brain-crawly sensation when I'm sleep-deprived. I worry sometimes that it makes me a zombie, but I think it's mostly in contrast to being less emotionally volatile again and also being stressed out by work and school. None of my friends or family have remarked on changes in my personality, unlike when I was on Lexapro. It has been a year since I started on it and I have no intentions of stopping anytime soon. It gives me the ability to actually relax fully at the end of a stressful day and quiets my mania, OCD, and anxiety.
I too am extremely sensitive to medications and blame a genetic predisposition. I am of Japanese ancestry and it's not uncommon for Japanese people to have mutations in bits of their genetic code in charge of processing medications. Some countries with a high prevalence of certain genetic variances have to put on their own drug clinical trials because what may work for Caucasian people may not work for east Asian people, descendants of certain branches of the African family tree, etc. You can be genetically tested through most doctors' offices now, I believe, and some psychiatrists may even order it for you. Without insurance it should run you about ~$150 USD, give or take $50 depending on what they're testing for. You spit in a tube, they send it away, and then you get the results 6-12 weeks later.