What will Brexit mean to our family?

[CalineF]

I am French. I have permanently lived in London since June 1992. I have paperwork to prove when I arrived and I can prove I also worked more than three consecutive years for the same companies over the past 25 years. I am not working a the moment due to chronic debilitating migraines. A relatively rare syndrome called HC and NDPH. All neurological treatments have so far failed.
I was engaged to a British man from Essex. John Smith is his name. I am not making this up!
We have a four year old daughter born in London.
We never married and separated two years ago.
I am the sole carer of our daughter.
I didn't apply for cityzenship. I didn't think I would need too.
Will I be asked to leave despite having leaved in London for twenty five years. Despite having worked and studied in the UK. Despite being ill and having no close relative. I am estranged to my family in France. Despite my daughter being British?
Have you any insight?

Apology I got the cost wrong: Citizenship by naturalization will cost £1236 with a further £1121 for your registration and £80 for your ceremony. If you wish to naturalize as British overseas, it costs £925 plus £833 to register overseas.

Children that register as British citizens are charged £936, plus £80 for their ceremony. Children that wish to register as British overseas have to pay £749.
echeck.org/get-uk-citizenship/