Suffering failure after excellence

As-Salamu `Alaykum Warahmatullahi Wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you!)

I am 17 years old girl in secondary three. Allah granted me success and I got 99% in the first semester, and now we have begun the second semester. However, since the beginning of the second semester I noticed that my vigor goes down, and I started to hate my natural scientific specialty after I had been loving it.

Unfortunately, I gave up my goal which was (a physic scientist) and now I hate it, and when the teacher starts to explain a theory, I start get boring and say: This is bullshit and not real. I do not know what has hit me?!

I got depressed and started to cry without reason. I had the feeling to delay everything, had the desire to commit suicide, and life has no meaning to me as it has become ugly in my sight.

I sat with myself and started to analyze the reasons, assuming that my problem with a female student has led to the deterioration of my psychological status as they believe I admire a mannish female and ill-think of me. I feel pain whenever they look at me thinking that I am in love with her.

I do not know whether there is a relationship between that and my hatred to knowledge or not. I do not see a connection between them.

Could you kindly help? Had not it been that Allah prescribed a punishment to suiciders and I know that my mother will die for me, I would have committed suicide.