THIS is exactly what I need to learn how to do. Unfortunately, it's much easier said than done. How did you start this new though pattern, did meds help you or did you just try to change your thought patterns?
I'm 65 and have dealt with panic attacks throughout my life. It all starts in the mind. Meditation helps but the thing that has helped me the most is learning to not care so much, i.e., adopting an attitude of Who gives a sh**? I consciously relax my body and then my mind relaxes. I've learned not to care so much about the outcome of things in my life. I've lowered my expectations of myself, I've learned to just shrug my shoulders and be more of an observer of life than a sweaty-palmed participator. LIfe is just too short to get all stressed out. Stop taking life so seriously, enjoy what you can, count your blessings and then relax and LET GO. SEE yourself relaxed and just go with the flow. You may still have a panic attack from time to time but don't let it rattle you... they will become fewer as your brain chemistry changes by a new way of thinking.
My one comment is that I'd do this with a psychiatrist rather than your GP. There's no guarantee a psychiatrist is going to be better, but it's usually the case. This is all they do. As to the Lexapro, for example, when I went on it my psychiatrist started me with 5mg and worked up, and you always have to know how to stop, as that's also difficult. GPs usually don't know how to do this very well. But good luck to you, I hope it all works out well.
You're right, your anxiety may get worse as your body adjusts to the medicine. Try the "start low, go slow" approach. Start with half a pill or maybe even a quarter. After a few days, take a little more. Gradually work up to the full dose over a week. Might take a couple/few weeks for it to start doing what it's supposed to do.