nervous about seeing my ex tomorrow at school

So my girlfriend of nearly 2 months (like literally a day off of 2 months) broke up with me because she had too many family problems and stuff like that. This happened over text as it is the holidays. So for the first two and a half days I was really upset and crying all the time. Then half way through the third day I got really pissed off. But then on the night of the third day I decided that I still wanted to be friends with her so I texted her a massive apology because in a previous text I was a complete bitch. She said that she still wanted to be friends and that she still loved me in a romantic way and I said that I felt the same. So we have basically been texting the same way as we did when we were dating (saying I love you etc.) She said that when this stuff with her family blows over that there's definitely a chance of us being together again. So now school starts tomorrow and I'm really nervous about seeing her. What can I do to make myself less nervous? Also why do you think I'm feeling this nervous? Thanks if you actually read this.

 

Yea I was a bit nervous when I went to my first class and saw her there but all went well.