Plenty of people hate themselves when they fail big time. It wouldn't be so bad if all that self-loathing could rebuild a better you in place of the one you have to deal with now. But it doesn't.
Self-loathing only marks the building that needs to be demolished. Tearing down the old you and rebuilding a better one in its place requires more than just you and your emotions. It requires a lot of hard work and the help of someone outside yourself to lift you up to get the job done.
So feel the feelings, but find the help you need and do the hard work. All the pity parties in the world won't do a thing for you, except make you worse off than before.