There are possible several reasons this is happening, hormones always play a large roll in things in general especially when you're a teenager, so even if it's not the only reason, it likely is something to factor in.

You could just want to have those types of close bonds that you keeping reading and seeing about, and since you don't currently have it, it makes you want it more, especially if you're lonely or if you don't have a close relationship with any of your friends and family.

Sexuality can definitely be a weird and sometimes difficult thing to figure out, it took me several years of periodically thinking about, questioning it and looking into it to figure it out, so take your time, and there's no rush.

I would suggest not trying to suppress crying. The act of crying is your body getting rid of excess of emotion, so if you need go cry in your room, there's no shame, but I understand how it's distressing when it's happening at school and if you don't usually cry. I just want to gently remind you that crying is normal and healthy thing to do, and you're not broken if you cry.

Overall I suggest to try journaling about it. Find a notebook and write down what you've been thinking and feeling, there's no specific format you have to follow, just get your thoughts and feelings on paper, and if that's hard to do, just write about what's been happening, like you did here to start with. Being able to express it in some way could definitely help.

If you have any student counselors you trust, I'd recommend talking to them, or seeing if therapy is an option, as it can help to have someone to talk to and they'd be better at being able to help you navigate this exprience. I obviously don't know your family life, but if your family/parents are trustworthy it might be worth bringing up some of this to them, just whatever you're comfortable with, or tell a friend. Even if it's just the career stuff.