You cannot hate yourself into becoming someone you finally respect.

Contempt is a poor engine. It can produce short bursts of effort, and it always sends the bill later, because every gain is delivered by the same voice that told you the gains were necessary to make you acceptable. Nothing you achieve under those terms gets to count, since the standard rises to keep you disqualified. Respect has to be built with a different tone.

Notice how you talk to yourself when you fall short, and ask whether you would use that voice with someone you were genuinely trying to help. Try the tone you would use with them instead. It is slower to start and it is the only version that lasts.