I had an mri after i was admitted to the er yesterday for hyponatremia. they found a very small benign mass on the right side of my brain. thoughts?

Benign brain mass : if it was an incidental and "benign" brain mass I'm pretty sure it's likely a Meningioma. That's a fairly common finding on CT/MRI and they are small and extremely slow growing benign tumors. They rarely cause issues and if they do it's usually many, many years (20-30) down the line and only cause problems when they start pressing on the brain. Very rarely do they ever need to be removed.