When a person is in self-hatred, aka self-loathing, they’re always the hardest on the people who love and care for them most. Because subconsciously they’re thinking “I’m such a bad/unworthy/unhealthy/’screw-up’ of a person, how could you love ME? YOU must be screwed-up!” And they behave and speak to you accordingly. I know it’s hard, but try not to take it personally. Your loved-one, for whatever reason (perhaps for a variety of reasons), is hurting. Patience, understanding, and maybe even some distance are what’s required, not more lashing-out.