I was good friends with a girl, and used to share all my secrets with her. At first she was very close to me, but then she found new friends and started avoiding me. I tried my best not to lose her, but finally we stopped being friends. She is going to join the same hostel where I stay. How should I behave with her?
Sounds like you are feeling awkward about having to meet this ex-friend daily in your hostel and don’t know how to behave.
The simple answer is ‘normally’ — just as you would with any other person… Ask yourself, ‘What makes me uncertain about how to behave?’ Is it because you have shared your secrets with her? Are you worried that she may try to make friends with you again?
If you want her as a friend again, it’s fine… but if you are sure that you don’t want that, treat her like any other acquaintance/hostel mate and be polite and cordial, limiting your interaction to hi/hello and general conversation. Focus on yourself and your needs, your studies, new friends, and your future. If she approaches you for friendship, be firm and say that you prefer to let the past be the past, and that you wish her well.