need advice about coming out and also a bigoted teacher in my school

So I am 15mtf, (currently male on all documents idgaf about documents really) and I live in Singapore. I need some advice on some crap that happened in school.

Firstly, I attend a school that i worked hard to enter to pursue my passion in math and science so i dont really wanna leave.

Secondly, my friends are all accepting of my identity and most of the teachers have other more important things to worry about so I don't get much nonsense for being transgender.

About a month ago, we had a Chinese New Year celebration and it is a custom on CNY to wear red things so i brought a teto wig that i made to school (I was in full school attire and just brought the wig) some random teacher who used to teach me(who I will call Mr F) pulled me out from the crowd and started berating me because "you look like a girl wearing this you are a boy and boys should dress like boys and girls should dress like girls" At this point only my closest friends knew i was trans but such an inhere transphobic statement made some other kid angry and he started screaming at Mr F who screamed back and they started a screaming match and had to be dragged out of the hall by the dean lmao

A school day later (there was a chinese new year holiday), I was buying coffee from the cafe when Mr F approached me again, pulled me into a corner and started his rant again.

I quote verbatim:"you tie your jacket around your waist with the zip side backwards you should do it forwards, girls do it backwards and boys do it forwards"
He then went on another crashout about shit i cant remember and using language that would get a professional fired.

At this point i just tuned out and only noted down what he was saying for future purpose.

The screaming incident in the hall became a disciplinary incident and I was pulled up as a witness. I explained all this in detail and sent a picture of the teto wig to the discipline master, and it took him a full ten minutes to understand what Mr F was saying, and he agreed that it was blown out of proportion by everyone involved.

this caused me to come out to my friends and now i express as female without getting shit but i still wear the male uniform and use the male bathroom because i want a nice clean record

So what should I do about several things:

1: when should i come out to my parents and how should i do it. they are not transphobic but they make a big deal of everything and are prob gonna throw a party or smth i dont want that

2. what are transgender rights in singapore, i cant find much cos of trump taking down all the sources and there just arent many sources in general

3. any tips for dealing with bigots

reposting from r/trans since nothings happening