Some foods are said to help, such as non-alcoholic beer, and Mother's Milk tea. Keep well hydrated also. You could speak to your doctor about it, too. I know in Canada there is a pill that is sometimes prescribed to help with the milk supply, but I don't know if it really works that well and also if it is even available in the US.
One of the foods that helped me was oatmeal. Good luck
Fenugreek!!! It works! I got it at GNC and can produce about 4 oz on each breast. Mother's milk works, but you'll have to drink about 10 cups of tea a day in order for it to have some results.
I had the same issues at the begining with nursing and pumping and never leaving either... Still to this day I produce half the amounth on my right side than what my left can do. I have tried exclusively feeding from the weak side, I have tried pumping extra times on the right. I tried taking fenugreek seen, more milk special blend liquid herbs, eating oatmeal, etc... No real luck here and it took me 3 months to get 36 4-5oz freezer bags stored up.
Now I am having to use them all cause I am still not producing enough in the evenings to statisfy my almost 8month old. When I am home we EBF, but I work M-TH 1p-midnight, so I pump 3-4x and am lucky to get 6-8oz from pumping.
Talk to a local LC and see if they can give you advice, you dont want to risk you supply on the good side, but they may have you pump every time after nursing on the limited side to help stimulate more milk.
Lots of luck and keep us updated if you find something that helps!!
I would recommend fenugreek and drink so so so much water. Pump after every feeding massaging each breast to get every last drop out. I posted a recipe on this forum recently for lactation cookies you can try those too