At first, I didn't deal with it very well because I didn't realize what was happening. I thought I had gone crazy, or was in the process of going crazy. Back then, the Internet wasn't as helpful as it is today (or harmful, depending upon how you want to look at it), or I would have Googled it; but I had heard about panic attacks through film and TV (The Sopranos, for example) and I eventually dragged myself into a bookstore to browse the self-help section (something the "before" me never would have done), and there I stumbled across books about anxiety disorders. After a few months of suffering, this was enough to motivate me to see a doctor. Of course, the doctor was familiar with anxiety, and suggested that I see a psychiatrist. This totally blew my mind. A psychiatrist? I was "normal" just a few months before. I had never even considered seeing a psychiatrist for any reason, so I brushed it off, thinking that I just needed to get it under control by myself.
So I spent the next year reading about anxiety, going through workbooks, taking supplements (another thing I had never done before), and trying to "gain control." Turns out, trying to wrest control is a bad way to approach anxiety; it imposes impossible expectations upon yourself--"If only I were smarter and stronger I wouldn't have these panic attacks. I just need to get it together." This kind of thinking makes anxiety worse. And it got worse.
Eventually though, I was able to find a better approach that involved accepting anxiety as a part of my life. I was inspired by something I had read about Zen Buddhism, so I began trying to view my anxiety as an old friend, my old torturer, my own brand of human suffering. Believe it or not, this worked. I began to intentionally do things that made me anxious. Axiety is much less powerful once you acknowledge that its roots lie in the brain, in the evolutionary drive to protect oneself from danger, and you can't consciously control it. All you can do is acknowledge it and move on, or "Feel the fear and do it anyway." I forced myself to reengage in life. I never stayed home when feeling anxious (I found this was the worst possible thing I could do); I accepted invitations to parties, I traveled, I enrolled in college, I moved.
But I continued having recurring episodes of severe anxiety that would leave me crippled for weeks: I couldn't sleep, I could barely eat, I had difficulty doing simple things like grocery shopping. So, at the urging of my family, I saw a psychiatrist (who was not helpful at all, as all she wanted to do was find out whether someone had touched my peepee when I was a boy. Hint: no one had), a neurologist (who was very helpful and very knowledgeable about anxiety), and a new primary doctor. My doctors coordinated to find a suitable medication, an SSRI. With this, coupled with my learned coping skills, I eventually began to feel "normal" again. A few years later, after experiencing no severe anxiety, I dropped the medication and was able to move on with my life.