help please!

I was 10:

a girl came on to me sexually.

Now, I'm 21.
And the porn that interests me is girl on girl.
where one girl violates another.

is this just a coincidence?
my problem is, I really can't remember how bad the experience was
when I was little

it could have been just kissing and fondling.

or, it could have been just fondling and nothing else.

I remember snapshots of it and specific words.

so, it just makes it hard.

cuz now I am extremley attracted to women
and I don't know if its because porn can like
change someones mind

or if its because of what happened to me

or maybe I just overanalyzed it all
I think I did...and then it made me even more confused.
the thing is, when i first looked at porn I had no idea
what would interest me

but, i immediatly only found interest in girl on girl
and usually a violation aspect to it.

also, I've never had a boyfriend.
so maybe whenever that happens all of this will clear up.

however...I am 21 and never had a boyfriend, so I am afraid it'll be
too late and I will be too attracted to girls by then???
I mean I have had the opportunity but I always turn them down.

help please!

There really is no worries about not having had a boyfriend by the age of 21. You are also trying to work out what makes you tick. And working out your true identity. I cannot comment if your experience at the age of 10 is the cause of your confusion, but I would recommend a few sessions with a T to work through these thoughts.
For me, girl on girl is very stimulating too.
I'm in a relationship with my boyfriend, but have had a relationship with a woman too. I think if you feel vulnerable, the gentleness of a woman is often what one looks for.
There's nothing wrong with being attracted to a member of your own sex.
Take as long as you require to work out what your identity is.