Greeting Surya-
Thich Nhat Hanh: True self is non-self, the awareness that the self is made only of non-self elements. There’s no separation between self and other, and everything is interconnected. Once you are aware of that you are no longer caught in the idea that you are a separate entity.
Thich Nhat Hanh: It brings you insight. You know that your happiness and suffering depend on the happiness and suffering of others. That insight helps you not to do wrong things that will bring suffering to yourself and to other people. If you try to help your father to suffer less, you have a chance to suffer less. If you are able to help your son suffer less, then you, as a father, will suffer less. Thanks to the realization that there is no separate self, you realize that happiness and suffering are not individual matters. You see the nature of interconnectedness and you know that to protect yourself you have to protect the human beings around you.
That is the goal of the practice—to realize non-self and interconnectedness. This is not just an idea or something you understand intellectually. You have to apply it to your daily life. Therefore you need concentration to maintain this insight of non-self so it can guide you in every moment. Nowadays, scientists are able to see the nature of non-self in the brain, in the body, in everything. But what they have found doesn’t help them, because they cannot apply that insight to their daily lives. So they continue to suffer. That is why in Buddhism we speak of concentration. If you have the insight of non-self, if you have the insight of impermanence, you should make that insight into a concentration that you keep alive throughout the day. Then what you say, what you think, and what you do will then be in the light of that wisdom and you will avoid making mistakes and creating suffering.
The above is taken from an interview with Thich Nhat Hanh in which he shares the Buddhist view of self and non self. Pretty self explanatory.
As far as Buddhism being Nihilistic, again I say they are not! The middle way seeks to eliminate the 2 extremes of Eternalism and Nihilism. Buddhist practice loving kindness and compassion. This is not Nihilism at all, sorry!
Finally, Buddhist consider Nirvana absolute happiness, not nothingness like you suggest.
Again, I will restate the I appreciate and honor Hinduism like I do all religions.
