So back in 2008, I was getting married and began having panic attacks and went through months of not being able to eat, sleep, constant anxiety. I went to see my dr back then and he prescribed me Lexapro (escitalopram) 10 mg along with Buspar. I can’t remember ever taking the Buspar because the lexapro alone took everything away and made me enjoy life again, this was the best I had ever felt in my life! 
Since I had never been through this before, I thought I was better a couple of months later and stopped taking it. 
A year later the symptoms came back and I restarted the Lexapro it didn’t work as well this time so the Dr put me on 20mg. That seemed okay but after a while it became ineffective. The dr then changed me to Celexa (citalopram) 20mg. That never did help me as much as lexapro 10mg did the first time. But I wasn’t in a constant state of anxiety just attacks sometimes but never was truly okay. 
I’ve been on Celexa 20 for about 5 years. Well a recent scary experience sent me back to spiraling. I saw a psychiatrist this time and she told me to try to up the Celexa to 40. I tried and on the 3rd day I was TERRIBLE. Couldn’t hardly stand for feeling like I was going to pass out, constant panic etc I was literally in the bed for 2 days and went back to square one with my original dose. When I again talked to the dr she told me that Celexa is not as good for anxiety as Lexapro and put me back on that at 10mg. She told me that just because it stopped working years ago doesn’t mean that it won’t work again. Also have me Buspar but I haven’t taken it yet. I’m on day 2, and take day 3 tonight. I don’t think I’m quite as bad today with constant anxiety but still have the sweaty feet, hands and anxiety thoughts just maybe not as severe as yesterday or the day before it that makes sense. I also have the option to go up to 20 after a week of taking 10. Has anyone ever been in my situation? Have you ever stopped taking something that quit working and went on it years later and it worked? I also plan to start therapy but have to get through this hump to even get any benefit from it as it would make me even more anxious to sit and explain this to a stranger. 
Thank You