Mental depression, panic attacks. Me.

Respected Sir/Mam I am suffering from mental depression from time to time since last 2 years and it is now crossing all the limits. All the problems started when I fell in love with a girl(Also my best friend at that time) who doesn't love me back. I told her and she refused my proposal. From that day till today I have been suffering from anxiety, panic attacks etc.I am not able to enjoy even some very happy moments of my life just because of this problem. I tried forgetting her by blocking her from every social media app but I failed as she is in my class and I have to deal with her everyday and act like i m okay to be her just friend. I love her,i deeply love her and sometimes i do senseless things just to impress her. I am now in the final year of graduation and now I have to study harder than ever but I can't concentrate on anything. I continuously experience panic attacks from time to time. Sometimes I can't sleep well, can't laugh well. I just can't get over her. Please help me.