Welcome to the forum and thanks for writing your first post.
It is a long time since I was in high school but I can relate to feeling I was ugly and student teasing me and making jokes at my expense.
I used to feel so alone.
I think that you are feeling sad at the breakup with your girlfriend.
Crying is a way to release your emotions.
Do you have a friend, or a teacher or a counsellor you can talk to.
When you are feeling up to it and , have you ever contacted
eHeadspace 1800 650 890 or online www.headspace.org.au/eheadspace/
Kids Helpline 1800 551 800 or online www.kidshelpline.com.au/get-help/webchat-counselling
Thanks again for sharing your story and feel free to post here as much as you like.