There is nothing you can do to treat thus with anything natural.
Methadone is very cheap...even if your insurance isn't continuing to pay for it, it doesn't cost more than $40/monthly
You should be able to getinto a methadone clinic because of your past history, of what they would consider, "abuse" of you're going off it immediately. Not that you're abusing it, however medically they would consider that on a drug treatment setting...
Going off that medication instantly could very well kill you, and that's no joke. Seizures and possible stroke...common.
There are other medications for withdrawal but they're very expensive, methadone I'd the cheapest. Either get the money for the prescription which is cheap, or find a treatment program.
You may possibly want to consider the emergency room as going of it cold turkey isn't safe...they could point you in the sea of a treatment center...the same kind they use for heroine addicts.