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.