I can get like this myself and have seen it in my friends. I have always wondered if it is just a matter of balance. I.e after years of focusing on others we go through a phases of totally focusing on ourselves etc...
I come from a place where my focus on others and wanting to help them and/or believing my life would be good if my A just did what I wanted totally debilitated me so while it may sound selfish, being totally self centred now and then is actually an improvement. And it does pass.