Oh hun that's a difficult situation. As someone in middle school now, I definitely remember how scared I was. I didn't want my period either, and I certainly didn't want to grow up. But, its a natural part of life, and we can't stop it. It just means you are maturing into a beautiful young adult. You seem like a very sweet person, and I am sure you will handle it well.
About your bi-ness (using your own words here lol), I wouldn't let it stress you out too much. As a genderfluid and omnisexual person, I was very stressed about my gender identity, but remember, you are still a kid. Right now, you should be focusing on homework and middle school. While it can be helpful to know who you like and who you are, if it becomes a problem and causes you stress, I reccomend you try not thinking about it. Remember, being bisexual isn't a choice, and it's something you are born like. Good luck :)
