Excessive Underarm sweating?

Nothing works. Anti-perspirants will work about once and then my body will like develop an immunity to them and I'll be sweating through them. Even the clinical strength stuff will not work. I have seen a doctor and the Prescription stuff will only work about once and then never work again. I'm desperate please help. My sweating has ruined at least 18 shirts in the past 3 months. I'm not considering botox or anything like that. But Is there anyway to permanently block your sweat pores under your arms? Thanks