does anyone know the best treatment for giardia?

hello, I have been dealing with giardia for the past few weeks and cant get it to go. Everything I eat makes gas, nausea and bloating and at the beginning I had constipation and now diarrhoea.
I have tried two courses of ayurvedic medicine, oregano oil, GSE, and neem oil and so far nothing has made a huge difference. I think I got some benefit from propolis but I by no means blitzed it.
can anyone tell me what they have found works best for giardia and is most specific for this organism? I am eating a really bland diet without sugar.
thank you!!!