I was diagnosed in 2016 after a manic episode. It was my first manic episode, prior to that I lived majority of my life either depressed or in a neutral state. 

I believe I was manic from March - June of this year. On a particular day in June I woke up in a depressed state and it didn’t go away until last week. 

One day last week I woke up feeling like a cloud was lifted off of me and I’ve felt really good ever since. 

I am able to tell you the exact date of the day I woke up depressed and the day months later where I woke up no longer depressed. Do episodes happen gradually or is it possible for them to happen so suddenly like this?