I want to begin by applauding you for reaching out and seeking help for your anxiety disorder. That is a very big first step in your favor. And from what you have said in your post, it sounds as if you have met some caring people that really have your interest at heart.
Regarding medications, I have a number of friends who are on Zoloft for their anxiety disorders, and they are doing quite well. Let me share a few things with you about Zoloft.
Zoloft is an anti-depressant that is classified as a selective serotonin reuptake inhibitor (SSRI). Don't left the term "anti-depressant" fool you. Yes, Zoloft can certainly be used to treat depressive disorders, but it treats anxiety too, and SSRI's are actually somewhat more effective treating anxiety than depression.
Your therapist was very wise to suggest that when starting Zoloft, you break the tablets in half and only take 25 mg to start. This can help to keep "start-up" side effects down. Now some people have no start-up side effects at all, others have a few, and some more severe, but start-up side effects can be very normal, and are not going to endanger you. They are not an allergic reaction. Some of the classic side effects include an actual increase in anxiety, insomnia, sweating, and upset stomach. These are caused by the Zoloft causing an immediate increase in serotonin. These side effects usually only last some 2-3 weeks, and then diminish rapidly.
And here is another suggestion for you. Don't worry about the lorazepam (Ativan) right now. When starting an anti-depressant like Zoloft, it is a good idea to take a benzodiazepine like lorazepam, to help manage any start-up side effects. I would be better to deal with the lorazapam later down the road.
And Zav, anti-depressants take a long time to work, so please don't be discouraged if you don't see any improvement for many weeks. It usually takes 3 to 12 weeks of therapy before degrees of improvement are seen, and that is once you are on a therapeutic dose of Zoloft. The lowest therapeutic dose of Zoloft is 50 mg. If you start on 25 mg, stay on that dose for 7-10 days, and then increase to the 50 mg. Most people that I know that are on Zoloft for anxiety problems, are taking 100-150 mg to see really good effects.
I am hopeful that I have helped you with my response. I am here if you need to ask me any questions.
The very best to you, Zav!... Chuck