I have a small brown spot on my upper lipline. it is somehow swollen and when i pinch it, it feels hard and painful.it looks large, underneath my lip.

See a Dermatologist: A brown lip lesion which has depth to it and feels like a lump needs to be looked at by a dermatologist. There are multiple reasons and possibilities. Therefore unless one is to see a picture of it or feel it with his hands it is impossible to tell you what needs to be done. I would not squeeze any longer. I wouldn't worry about it since brown spots on the lips are common but it needs to be seen.