Had addiction of cannabis want to leave it

I’ve been using cannabis for almost 10 years — tried quitting several times but kept relapsing every few weeks. Recently, I became more serious and committed to quitting. I consulted a neuropsychiatrist who prescribed lithium, but after 3 months, it didn’t help reduce cravings or change my habit. When I questioned the prescription, I was dismissed from the clinic. Now, I stay clean for about 20 days before the urge returns due to easy access and psychological habit. I don’t believe I need lithium, but I’m looking for the right treatment — whether it’s medication, therapy, or another method — to help me quit fully and sustainably. I am from dhanabd and can't come to your clinic can you suggest a good medicine to stop this urge I get in 20 days or should I use lithium only as I have read its for some kind of disorder and depression whcih i dont have atall