Sudden panic and paranoia onset

I have been a sensetive person with anxiety and health problems my whole life. But panic attacks were always triggered by something. But just recently while trying to fall asleep, I had what I think was a full blown panic attack. I was dizzy my heart was pounding and I just feel super tense and paranoid in general and I have no clue why. I’m super stressed as any 18 year old college student trying to balance a 4.0, a job, family and friends is. Can someone d please tell me why I felt panicked for no reason? Is it possible to have panic attacks with no immediate trigger?

There may not have been an immediate trigger, but it's probably a result of a lot of stress building up. Your brain is overloaded on stress and the panic attack is essentially a sign that something's got to change. It's your brain saying "de stress yourself, something's wrong".

Don't be scared of this. If you fear it and try to ignore it, it will only get worse. You have to relax yourself through it and know that you're not dying, and it will be over soon. It's hard to cope with at first, but you'd be surprised as to how easy it is to get used to. Keep in might that anxiety feeds off of fear, the more fear you have of it, the stronger it'll grow.

Personally I've been on Celexa for close to 6 weeks and I do have bad days, but the anxiety is easier to manage and combined with knowledge of anxiety and why it's there, doesn't control me anymore. If you find yourself feeling hopeless or depressed from this, I strongly advise you talk to your doctor about medication. Best of luck!