I have had this problem for several days so far. I cannot log into my Mojang account. I know to log in with my email address and I know for a fact my password is correct. I have even changed it multiple times. I have also tried my brother's account and that doesn't work either. I have also tested this on three different computers. The weird part is. It only doesn't work on my home network. I brought my laptop to a friend's house and was able to log in to both accounts successfully. I have tried logging in through the launcher as well as Mojang.com and Minecraft.net. I am almost positive it has to do with the internet connection at my house. I have tried updating the router but I have yet to reset it. Does anyone have any suggestions on fixing this problem?
Given the information you have given us, I think the most likely scenario is that you have a firewall/ some sort of internet blockade up. Try to remove a firewall if you have one. Is you ISP different that your friends'? That might be an issue too. Also, try your real MC username and your email for the username field.