What is the best medication used to effectively treat these anxiety/panic symptoms?

I have been on lexapro 20 mg for almost 2 years because of depression, but recently I have been feeling like maybe its not working??? i am wondering what actions to take to get on a good reliable medication that will treat these symptoms:constant tension, worry, (i also have been diagnosed with adult add)-the lack of concentration and drive to do daily activities, low energy, some days i will only get 2 hours of sleep while others I could sleep all day and still wake up tired as hell. I am always tired, and lately i think i have been having panic attacks...in a stressful situation-mostly when i interact with other people. I get this like paranoid feeling that I doing something stupid (maybe i am who knows, i sometimes care...sometimes i don't) or that other people are thinking that I am crazy by the way they look at me or talk to me. i know its wierd. But the anxiety is really start to eat away at me here lately. I don't understand why this happens, i used to be the cont'd.......