I would wait and discuss this with your CBT therapist. Some require you to see a psychiatrist first to see if medication is necessary for progress to happen and some don't like their patients to be on medication at least to start. I think it depends on how able you are to function. As for Xanax, it's best taken only as needed, as it's very hard to stop taking if you take it regularly. Side effects are very individual so it's hard to predict, but benzos biggest side effect when you're taking them is it might make you tired. The hard part is when you want to stop taking them, which is much easier if you, as I said, just take it when you absolutely need it. My CBT therapist didn't want me on medication, but later decided I should after gauging my progress. The whole point of CBT is to face your anxiety head on, so that's why some prefer no meds. But there are other places I've inquired about over the years that, as I said, require you to first see a psychiatrist, so they're not all the same.
My dr prescribed me Xanax. Should I take that and what are the side effects?
That depends on the person and the practitioner. Keep your expectations within the reality of psychotherapy, which is that it only works when you connect with the right therapist. So it could be very quick, and it could take awhile, and it could take a couple of tries before you find the right person. Meaning, if it doesn't work the first time, don't give up, keep trying. But expect that it will.
It is a long process? How many sessions on average it needs to be effective?
It's a bit confusing at first. Just ride with it if you can for awhile. And the most important part is attitude, which I wish I'd known when I did it. You have to accept it won't work right away necessarily, that you have to keep trying, another thing I wish I'd known when I did it.
That is great that you are going to go to therapy. I believe the most crucial step in confronting this challenge is by learning about it. In my opinion, we tend to fear what we do not understand. While every therapist approaches CBT a little differently, the big thing is you are going to gain the knowledge and the tools to deal with this...for me, it is all in the interpretation of our feelings of dread, fear, etc.