As a 'far left white' myself, let me help you understand!
First, my support for BLM isn't about 'white guilt'. My family is poor, protestant Irish trash from way back. We can trace our ancestry to the flood of immigrant labor that settled in the Appalachians. We have ancestors who were indentured servants, and who fought on both sides of the Civil War. None of my ancestors owned slaves, though. So why should I care about slavery or reparations? Because people alive today are descended from people who were mistreated for no reason other than the color of their skin. Because the systems I benefit from, as a white man, are DEEPLY racist in structure and execution. Because today, a poor black man still gets arrested and his life and family get destroyed over an offense a rich white boy gets a slap on the wrist for. Because police assume violence and respond accordingly when there is any melanin in a crowd, but shrug and do nothing for a white crowd. Because black men and women are murdered by cops who should know better. Because black voters are STILL being disenfranchised by white 'conservatives' I care because real people are being harmed by our cultures continued refusal to look at ourselves and accept responsibility for 'our' part in this.
Next, my support for queer issues is personal. I have several queer family members, and am, myself, queer. So my support for LGBTQ+ issues stems from personal connections to, and an understanding of, the REALITY of queer issues.
Additionally, my support for choice, autonomy and women's health issues comes from several places. I myself have been, and people I know and love have been raped, and not been taken seriously by law enforcement and family. I have family members who have had abortions, for various reasons from rape to health issues to simple poor timing. I have educated myself on issues concerning autonomy, choice, and women's health and how poorly medicine in America tackles the subject (to say nothing of media or government) because the women in my life are important to me.
I care about racial justice, queer rights, women's rights, education, the environment, health care...because those issue MATTER. It isnt some 'woke' performance of guilt. It isnt about hating myself. It's about wanting to make sure the world is safer and better for future generations. It's about being willing to sacrifice my comforting ignorance in order to do my part in making sure that my ignorance doesn't infect future generations. It's about empathy. Thinking how it would feel to be in the shoes of another.
Is some left wing wholeness performative? Absolutely. But that doesn't make the concepts they talk about less real. If you can't understand that, then...maybe you need to do some real soul searching.