Confused about my sexuality. Have questions. Please help.

I’m a female who has never dated anyone before or had sex. I’m mostly attracted to guys. I’ve never felt attracted to girls until I was 20. I was staying at a female friends’ place and all of a sudden, out of nowhere I got the strongest urge to pin her against the wall, hold her hands firmly above her head, and kiss her. I felt this strange feeling, like an intensity or adrenaline rush that I've never felt before for any girl. Immediately, I was so shocked at myself. I don't know what came over me. I don’t actually like that girl sexually or romantically, so I don’t know why I felt that. After that, I’ve been checking out girls more. I also get turned on by seeing a naked women, seeing physical intimacy between women sometimes, seeing big breasts, etc. I've also started masturbating to the thought of women and have been able to orgasm. There aren’t many women that I feel attracted to, but there are some. There’s only one girl that I would actually have sex with because I just find her so hot. I'm not sure if I could spend the rest of my life with a girl. I feel that I need the dick or that I would miss it. But then I think of strap-ons and get confused. I’m not sure if I would miss being with a man. I’m guessing that if I truly love the woman, then it wouldn’t matter.

1.    Is this a normal thing for straight people or is something mentally wrong with me?

2. Do you think I actually do like girls?

3. Could I be having these feelings because I’ve never had a relationship before and I really want to be with somebody so my brain is going with anyone?

4. How do I know if I like girls or if I’m going through a phase or wishing things?

5.    Is it possible for bisexuality to just "switch on" like that?

6.    I want to experiment with a female to see how I feel. How can I find someone who is also willing to experiment?

*Edit: thank you so much switch switch bitch, Sammy, and N. Your responses have helped me so much. I've finally found much more clarity and have a better understanding. Thank you for making me aware of the terms bi awakening and compulsory heterosexuality. I finally have the answers I've been looking for so long. I truly appreciate that you took the time to read my long question and answer it in such great detail. Thank you.