I started taking lithium and i feel so drained i'm so tired don't feel well, etc how long will this last, what would you recommend?

Lithium level : If you haven't taken your lithium tonight, i would recommend that you hold off on taking it and contact your psychiatrist tomorrow about getting a lithium level drawn. If there's a walk-in clinic you can perhaps go to a walk-in clinic and have a lithium level drawn as well. It's unusual for someone to feel this early on in treatment. I don't know what dose of lithium you are on so i can't tell you whether it's a relatively high or low dose, but i can tell you that it is definitely necessary to get you checked to make sure that you're not having lithium toxicity.