Just forcing isn't always enough. It requires your mind to be open to alteration too. The problem is that social situations are a negative experience, by learning alternate ways of viewing the situation, you start to turn the negative into a neutral- or even positive experience.
That's why many recommend a therapist in conjunction with going into actual social situations; because therapists can help you learn those alternate ways of viewing the situation. And, potential help you resolve the thing that has caused your phobia to manifest in the first place.