I don't know about self-loathing. I don't loathe myself. I know that, whatever faults I may have, I am better than most and am trying to curb the shittiness of persons such as yourself. I don't contribute to (or at least I consciously try to limit my contribution to) poverty, suffering, destruction of the planet, etc.
So, no, I don't hate myself. I just hate you. And that hate for you doesn't drive or motivate me to do much of anything but feel sad. It's my love for other human beings and for life itself that motivates me to be a leftist and to work hard to further leftist causes.