Hi, I'd like to help you with your question.
You should not have any different reactions with the Zoloft now that you had in the past. For the most part, medications will work the same and have the same side effects each time you use them. If you went off Zoloft because of side effects, then you may want to try another medication. Most people who take medications usually have to try several different ones before they find the one that works for them.
If you feel anxious about the side effects of any medication you take, be sure to research it thoroughly. You will not get most of the side effects of any medication you take, but it helps to know if there are some that concern you. That way, you can talk to you doctor about your fear. Doctors hear that a lot, so it is not unusual. It is their job to help you feel better.
Although medications are great in helping with your symptoms, they do not solve the problem of why you are having social anxiety. Have you considered seeing a therapist? Talk therapy has been proven to be the best way to cure or greatly reduce anxiety. And anxiety has a very high cure rate with therapy. Both Cognative behavioral therapy and the newer Integrated therapy have been highly effective in resolving anxiety. To find a therapist, talk with your doctor for a referral. Or search on line at http://www.goodtherapy.com.au/find_a_therapist.php or http://www.findatherapist.com.au/.
You can also help yourself at home. Here are some resources to get you started:
The Shyness & Social Anxiety Workbook: Proven, Step-By-Step Techniques for Overcoming Your Fear by Martin M. Antony and Richard P. Swinson
Overcoming Social Anxiety and Shyness: A Self-Help Guide Using Cognitive Behavioral Techniques by Gillian Butler
A Life Less Anxious: Freedom from panic attacks and social anxiety without drugs or therapy by Steve Pavilanis and Patricia Alma Lee
You can find these books on Amazon.com or your local library may have them for you.
I hope this helps you,