I do believe your tremors are caused by Wellburtrin too due to its stimulating proprieties affecting the reuptake of dopamine and norepinephrine.
I suggest a lest stimulating antidepressant or see if you can go without Wellbutrin.
For your condition a think a good treatment could be Lexapro and vitamin B6. I don't know why you have been treated with Wellbutrin in the first place since PMDD is more likely thought to be due to a lack of serotonin but no one knows for sure, the evidences are based on responses to treatments.
Also consult a qualified physician before making any change in your medications let it be a prescription drug or a supplement.
M4
Perhaps you can discuss a reduction in the dosage with your prescribing doctor.
Maybe a small reduction will be enough to end the tremor. If you make a small reduction and still feel well after a month or more, you can try another small reduction and see what happens again. It's about the only way to find out if you still need the medication.
Let your doctor make the reduction decision with you and give you dosage directions.
Take care.