Nocam

You did not make a mistake getting getting radiation and cisplatin the first time around. Take a look at DavidCPA's posts and signature line: that's what he did and it worked great. A second opinion would more than likely have advised the same course of action.
Even for smokers who have base of tongue (BOT)cancer, the preferred treatment is to avoid surgery as much as possible since for BOT the surgery is brutal. It is usually reserved for recurrences.
I had my jaw split open, my base of tongue cut out, a flap from my wrist transplanted to the base of tongue, a flap from my groin transplanted my wrist to fill in for the wrist transplant. The location of my tumor and the size were considered not suitable for TORS. Unfortunately, the pathology report post surgery showed perineural involvement so I needed even more radiation and chemo which left me with more complications than you should have. My ENT surgeon does this type of salvage surgery about once a month and it is indeed important that your surgeon have regular experience. Good luck
charm