Ask a doctor or pharmacist.
Anxiety and panic causes stress and this brings on short term memory loss. you need to see your doctor, he can give you something for the panic attacks, as to restoring your memory loss, I am not sure there is anything that will help with this.
For every child, treatment may vary, what may be a wonder drug for one child may be a complete disaster for another, and sometimes meds used off label (i.e., they weren't intended to treat anxiety/panic) may work as well. it is important that you work with a medical professional when using medications for treatment and creating a treatment plan.
You may want to follow the research on a medication that is currently in trial at this time, STX209, clinical trial is going on for Autism and Fragile X, the study med is based on Baclofen, a med that has been on the market for years and is available. We've participated in the clinical trial and the medication did much more than just treat irritability, my child was in school during the time he was on the study medication and he improved in eleven different areas on his progress report.
Also, there is a new drug that will come to clinical trials in 2010 that in the animal model reversed symptoms and improved cognitive ability, see details below from an article in Time Magazine for more information and for more technical information visit Seaside Therapeutics.
I also encourage you to follow the research from Seaside Therapeutics, treatment options for autism and fragile X are rapidly changing.
Marijuana
Black Coffee.
Possibly St John's Wort. A very judicious use of anti-anxiety herbs– they can have a rebound effect that would be worse than the original panic. this is why people recommend doctors; any herb/drug that helps may hurt if not used VERY carefully.
I don't know any specific medication but I do know a book which can help people deal with Autism. Not only that, it also gives you information on what it is and how to deal with it. My niece was diagnosed with autism when she was 6 and it's been really difficult for her family. They said they have started reading this book and it made their lives a bit easier. I hope this book can help you too.