I have been diagnosed bipolar 2 and take a mood stabilizer regularly. are there any natural supplements i can take to help with my downs?

Maybe: There might be some that will have a minor effect on your downs, but these should be coordinated with your prescriber as there can be adverse effects. For example, st. John's wort has long been confirmed as a "natural" antidepressant. But that's because the plant synthesizes an antidepressant chemical little different than one made by a pharm company. These are known to provoke mania.