I get so frustrated with how I experience depression. I was wondering if anyone can relate, or if it sounds like something else.

I feel that it comes in waves of 4 months at a time and follows a similar pattern.

First month- I start off slow but motivated. I cope and make plans.
Second month hits a high with some sort of personal revelation. I get very anxious but work hard on this goal. During this time I will have issues sleeping & I'll go to bed somewhere between 1am-5am. Not surprisingly I'll experience health issues from the sleep disturbance.
Towards the end of month three I will become less motivated in all areas of my life, and question my choice that I was so excited about previously. This usually leads to feeling more acutely depressed.
In month four good days feel like blah and bad days are the norm. This cycle usually ends with a major depressive episode that can last a day or a couple months. After that the cycle starts up again.

Over the years I've seen a handful of therapists and have been diagnosed with depression and anxiety. I'm currently taking a low dose of wellbutrin that I've been on for 3 months. It helped pull me out of my initial depressive episode but now I'm dealing with insomnia and plenty of blah days with the depressive habits, thoughts and feelings creeping into my life. In the past I've tried other meds and still experienced this cycle.

Does anyone else experience this?