That does seem tough. I do sympathize. However, your diagnosis of the etiology of your distress at how things have turned out is off-beam.
You've successfully (at least in your own mind) pretended to be female for a good while; now matters outside your control seem likely to put pressure on this pretence, you are (naturally) upset by this turn of events.
But the court ruling wasn't "arbitrary" (leave aside your "funded by ..." and "army of ...": that's just (misjudged) anger at what's happened). The court ruling explained what the law always was - what the Equality Act had to mean regarding "man" and "woman" and so on if it was to make sense at all. But why was the court called upon so to rule?
Your pretence, and that of others in similar circumstance, used to be winked at by the rest of us. Now attitudes have hardened, possibly to your detriment. Why this hardening of attitude? Why should we suddenly wish to insist on the fact (and it is, after all, just that: a fact) that you are, as you have always been, a man?
-- Not a sudden outbreak of hatred at difference, or some sort of phobia: no, rather it's been that societal acceptance of the pretence in question has been weaponised by bad actors - to the severe detriment of a cohort of children, in particular, and in attacks on the rights of women.
The blame for your current distress needs to be laid at the door of these bad actors, and not the women whose hard-won rights are under attack, or those who care about the welfare of children.
You may well not be one of those bad people (we can't really tell). So, I'm conditionally sympathetic.
But lay the blame for your predicament where it's due. Not the women of Mumsnet; more the TRA's of ... well, wherever, I dunno. (SNP? Reddit? Stonewall? Sussex University? ...)