1. I'm debating between... [option A and option B] 2. I can't make up my mind. 3. I'm on the fence. (= I'm in the middle, I don't know what to decide) 4. I'll take that into consideration. 5. On the other hand... 6. I'm having second thoughts. (= I'm reconsidering my decision) 7. I changed my mind. 8. He convinced/persuaded me to... 9. Looking back, I know it was the right decision. 10. It's up to you. (= You can decide)
There are two basic, unspoken rules when it comes to how much you should speak during the speaking section. The first is to speak as much as possible; the more and the greater variety of language you use, the better. You dont want to talk incessantly and repeat yourself just for the sake of talking, but you should try to speak as much as possible within reason. As long as the conversation is lively and interesting, you cant talk too much.