Hi Will, and welcome to Anxiety Zone!...
A good place to always begin, is to see your regular physician. Discuss your symptoms with your doctor, and rule-out any underlying physical conditions that might be causing your anxiety. These can include thyroid or heart conditions, to name a few.
If physical conditions are ruled-out, your physician can treat you for anxiety/panic attacks/depression. I choose to have a psychiatrist to take care of my mental health issues. Mine has provided me with a diagnosis, has me on an anti-depressant, and has a detailed treatment plan, structured just for me.
Often times it is not apparent as to what the cause is for one's anxiety, and one merely finds themselves in a cycle of anxiety feeding anxiety. There are solid treatments that can help those with anxiety/panic attacks/depression.
Treatments that are known to work include the anti-depressants, such as Celexa, Paxil, Remeron, and Viibryd (to name a few), therapies, such as cognitive behavioral therapy, exercise, and omega 3/fish-oil. There are also many other activities that one can do, to support the healing of the mind. These include keeping oneself hydrated, drinking plenty of water, a healthy diet rich in whole grains, fruits and vegetables, meditation, and mindfulness.
The very best to you, Will!... Chuck