All my life. I'm in the US, and many (not all, but so many!) women here seem to regard other women primarily as competitors, therefore enemies from the start.
I didn't have that problem with males until I hit my prime working years, when *some* but by no means most of the men I worked with started that same competition-therefore-enemy thing in workplaces.
I think the US culture is unhealthy in terms of being overly competitive in many areas. So depending on where you are, your experiences may differ.
Good luck to you. One solid, true friend - male or female - is a treasure beyond price.
_________________
"I believe you find life such a problem because you think there are the good people and the bad people," said the man. "You're wrong, of course. There are, always and only, the bad people, but some of them are on opposite sides."
-- Terry Pratchett, Guards! Guards!