Hello, I Have Been Experiencing Several "mood Swings". One Day

Hello, I have been experiencing several "mood swings". One day I'm so sad and feel as if the whole world is up against me. The next, I can't get over myself. There's times were I'm jumping with energy and I've been so tired lately. I fall asleep as soon as my head hits the pillow but still wake up sleepy. I've experienced depression for the last two years. On a recent trip to a water park, I had an anxiety attack. All these mood swings really scare me and I've been wondering if it could be depression? My memory is beginning to fail me and I can't think straight as much as I used to.