No he doesnt ! What Sartre calls Nausea is the feeling a person will experience when for a moment they realise that they are free and at that point it will become like staring into a void like abyss, at this point one realise that ones choices are open and that the person is indeed living an authentic existence. This becomes too much and one recoils from the abyss and prefers an inauthentic existence. The difference between authenticity and inauthenticity you must read for yourself as it requires an understanding not suited to a forum- So its,er.. very little to do with Nihilism actually. according to whom? No it isnt, clearly your last sentences are about some Bhuddist text that you havent properly understood. Can I suggest that you read Sartre for beginners. Also there is a very good book called Existentialism for beginners. If you want to dive straight in to sartre I would not start with his novel called "Nausea", but his academic papers called "Freedom and Responsibility" a collection of essays about freedom and authenticity and responsibility
