Just keep trying. Chose the option that doesn't result in a bite, and if you are going to get bit anyway, pick the choke option. Then it depends how you want it to end, but when you get the tigeress down to a certain amount of stamina, there will be an option to either stop and think, or not think and just throw her in. I'm not sure about the throwing in path, but for the calming one, pick the option that is successful. There will be the option to go back when you get to the giant fight, so you can go back and forth between choices. There is quite a bit of luck, so if you find you have lost the fight, just reload the save from the start of the fight and try again. But yeah, for the option to save the tigress and yourself, mix up the calming and talking sense option. If one of the options send in a bite, choose the other. If they both end in a bite, choose the calming one. You should be able to get it eventually. Then the options after are quite easy. The calming option in the saving both yourself and the tigress leads to the success.