Does it really help if I use incognito mode in my browser?
Not really. The only thing that incognito mode does is forcing browser not to save anything that you are doing at the moment (cookies, history etc.) beside downloaded files, of course. Your ISP can still identify you and see what you are browsing. Try Tor browser, it might be slow but that's because of how it works.
I would also recommend all to delete their Facebook accounts. This company is irresponsible, and we can't count on them in the matter of privacy.