I can't tell from your post if your mood is cycling between mild and major depression or if you are going hypomanic as well. If it's just depression an anti-d may do the trick. The newer anti-d's like wellbutrin tend to be better for people diagnosed in comparison to SSRI anti-d's.

If your mood is going up and down the addition of any anti-d may not be the best idea. You may need the lamictal increased or may need an add-on med for the lamictal like abilify. Many people that are on lamictal need an add-on med because the lamictal isn't as good at controlling the highs.

I'm on wellbutrin. I prefer the XL, but it doesn't come in a dose lower than 150 mg. I was getting too high even on the 150 mg since my med change to lamictal.

I'm sorry you are having a hard time.