Just a couple of more thoughts on this topic. It's possible to have mood swings but not be bipolar.
I was having mood swings - periods of non-productive energy that pretty well fit the description of hypomania. That's when my Primary Care started me on Lamictal and referred my to a psych ARNP. We've since determined that it wasn't really a bipolar condition. A few months later my PC found a very severe vitamin D deficiency. I think the SSRI and the vit. D deficiency combined in a bad way to give the hypomanic-type periods. So there might be an underlying condition that is aggravating the mood swings.
I think I'm considered as having treatment-resistant depression and have stayed on Lamictal.
Another thing I experienced was a serotonin-high as I phased wellbutrin in and out and it was combined with another SSRI. Very unpleasant and hypomania is also a pretty good description of how I felt.
It's a little difficult to know exactly what was going on cause there is likely a psychiatric component to my Lyme disease. At the time we didn't know I had the Lyme. The Lyme is being treated and I hope the anxiety/depression/mood swings even out eventually. Killing of the bacteria with antibiotics releases toxins and it aggravate the psych symptoms.
Hope you're able to unravel this and smooth out the swings. I just hate hate hate the excessive, non-productive energy of the hypomania type episodes I was having. Made me irritable and took all my energy to stay calm. Not like I could use that energy to concentrate and be productive. Did I mention I hate that excessive, non-productive energy?
Hang in there!
edit - sorry, I'm just not able to remember everything at once. Oh well. Vitamin D and B-12 deficiencies may be related to irritability, depression and mood. If you haven't had a complete blood workup in a while, maybe it would be a good idea? I never expected to have such a severe vit. D deficiency.