What is my mother tongue?

I was born in Antwerp, Belgium. Although the local formal language is Flemish, at home and with my friends I spoke exclusively French. Most lessons at school were in Flemish, and so was the language we had to use on the streets.
At the age of 13 we moved to Israel. With my family I kept speaking French, but everything else was Hebrew. Well, except for my baby sister, who was 3 when we moved to Israel, so with her I speak a mix of French and Hebrew. All my studies from high-school to Masters Degree were in Hebrew.
For 10 years now I have been working with computers, all the scientific and other professional material I read is in English, 99% of my mail communication is in English, I like to read books in English, etc.
I type at least 10x faster in English than any other language.
I read the fastest in English, then French and rather slowly in Hebrew.
There is no language I can (hand) write such that other people than me would be able to decipher what I wrote. And that's when write slowly.
When I write (or type) in French, the mistakes I make suit a 13-year old.
I dream usually in either French or Hebrew, but once in a while I even dream in English.
I speak Hebrew with my wife and French with my child.
People say I have a Hebrew accent in French, a French-Belgian accent in Hebrew and a mixed French/Hebrew accent in English.

Now you tell me - what is my mother tongue?