Biological sex is real, and "gender" is a word currently used to mean a feeling, a desire, a fantasy, or a whim.
I see you are still denying the legally accepted definition of gender.
Here is the UK's explanation of gender for your perusal.
Under the
Gender Recognition Act 2004, a person can officially change their legal sex (male/female) by obtaining a Gender Recognition Certificate (GRC). The Equality Act 2010 protects against discrimination based on sex and gender reassignment.
You'll notice it does not include the words 'feeling', 'desire', 'fantasy' or 'whim'.
This is why your belief is fanatical, it is in direct contradiction to the legal framework of most countries.
Sex is a label applied by the person in attendance at a birth. Most countries require such a label be assigned at birth. But many countries do not, e.g. Canada, Malta, Germany, Australia and Austria.
Such legally required assigning of the sex label in such short time periods gives rise to errors, and in the case of an intersex baby and a specific binary sex label being required, an IGM procedure to "correct" any biological mistakes, is required. This is without the consent of the patient.
You're obviously quite content for such procedures, to artificially create the genitals of intersex babies to conform to the doctors or parents requirements, to continue without the permission of the patient.
Having a whim does not turn a man into a woman.
Being assigned the incorrect label at birth can cause body dysmorphia, and other issues, such as cross dressing, etc.
The person adopts the gender of their choice, correcting the process they were denied at birth.
If you think the word "woman" includes "person who is not a woman" then you are incapable of understanding what words are for.
Woman is a word for sex or gender.
You can call yourself a giraffe if you want to, but you are not a giraffe.
Words are social constructs.
Due to your inability to understand the meaning of such words as 'woman', 'man' or 'gender', I wouldn't expect you to understand the meaning of 'social construct'.
'Giraffe' is an English word. It has no meaningful significance in any of the 7,000 odd languages spoken. globally. It only has meaning in an English speaking society.
I'm glad I could help you.
You are the one needing psychological help to deal with your fanatical belief which is contradictory to to modern day biological knowledge and medical science.
And still you are unable to posit a rational or scientific argument for your TERF'ism.