I'm sorry you are in pain and that you wait so long for an appt to see a neurologist. I understand that it's a bad situation and I sympathize with you completely but there is no way I could make the suggestion you are asking. I'm pretty sure no one else here is going to feel comfortable doing that either. If anyone did that they would have their post deleted and receive a stern warning from site staff. I'm sorry but this is a support board and nobody here is qualified to make the suggestion you are asking for.
You need to find a way to get in touch with the doctor who prescribed the lithium or with your primary care doc if you see more than one doctor. Your doctor is the only person qualified to give you advice on medication. I wish you well.