Lithium orotate is not a substitute for lithium carbonate. Please check the details here: http://en.wikipedia.org/wiki/Lithium_orotate Just because it's OTC does not mean that it's risk-free, an appropriate treatment, or effective at all!

Lithium carbonate is very, very cheap as a prescription medication. But you do need to see a doctor, make sure you actually do need it, and if you end up taking it (there are other meds that may be preferable, many of which also have very cheap generics) then you also need to have your health monitored to make sure your body keeps functioning properly. No psychoactive meds should be taken without medical supervision!

Kindachaotic mentioned a number of resources - it's a hassle, but it's a much better idea to get medical help than to try to treat yourself.