When just starting therapy for social anxiety, it's impossible to go from our normal way of thinking to positive thinking right away -- it's too much information for the brain to take in all at once, and so your brain won't accept or believe it. Instead, we have to slowly ignore our old thinking habits, and change our negative thinking in a step-by-step way. You shouldn't try to make super "positive" affirmations or statements to yourself right away, as they won't work because the negative thinking habits are too deeply ingrained into your brain at the present moment, even though it is not your fault.
For example, if you make a statement like "I will be able to talk to a group of people comfortably," and realize this statement is too positive for you to make at the present time, add some neutral or conditional word like "maybe," "possibly," "perhaps," or "it could be the truth that," into the your statement. For example, you could instead say, "Maybe, over the course of doing the therapy, I will be able to talk to a group of people more comfortably than I am able to now."
By making a statement like this, you are staying rational by telling your brain something that it can accept, and this opens up your mind up to the POSSIBILITY of this happening sometime down the road. We do, however, want to stay away from setting an "exact" deadline for when we should accomplish / feel this, as that would just add pressure to the situation).
So the key is to stay away from absolutes, whether negative or positive. You should stop saying you HATE making presentations, even if this is how you currently feel, because this only reinforces your hatred and anxiety about making presentations. Instead, say "Right now, I dislike making presentations, but MAYBE it won't be so scary for me if I keep doing the therapy in the appropriate way. Maybe I will feel more comfortable making presentations in the future, and I may even enjoy making them eventually." THOUGHTS must be changed step-by-step like this. You can't go from negative thinking to positive thinking overnight.
We use this in our audio therapy series and the local and interantional group programs -- and it works very well if we keep doing it. Most people are actually surprised at the changes that occur in their own thinking and behavioral patterns, after having practiced this therapy method with persistance, determination, and a compassionate attitude towards themselves at every step of the process.
These same changes can happen within you, if you are persistent, determined, and compassionate with yourself while you work on changing your thoughts from negative anxiety ridden ones to more neutral, and eventually positive ones. You will start to feel more positive and happy as well, as long as you keep turning the tables on your old thinking habits. You can never fail at this unless you give up, and thankfully very few people with social anxiety give up.