Dear,
Welcome to HCM
We understand your concerns

I went through your details. You must be able to understand Concentration, attention span, recollection and distraction. If you are able to watch a movie for two hours continuously, if you are able to play a game for an hour, then you do not have any concentration problems. You can't be attentive towards your studies because you are not interested in it. You are able to watch movie and play game because you are interested in it. Human cannot be attentive towards anything for more than 10 minutes. If the task is boring, it is natural that that person will sleep or feel sleepy. Then you should study in such a way that your attention is continued and make the subjects are interesting to you. Effective learning techniques should help you. Recollection depends on anxiety, stress and other physical and circumstantial factors. Distractions while studying are plentiful. You should be able to overcome distractions or avoid distractions. Please understand the above. Change your study style and attitude accordingly. Please search internet for "effective learning" techniques.

I strongly suggest you to change your attitude towards your outlook and life. A good counseling session will help you immensely.

If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute detail possible.

Hope this answers your query. Further clarifications are welcome.
Good luck. Take care.

Well, from seeing your question I am to assume that you are in high school or in college, as you have not mentioned your age and sex. Usually during this age group being attracted to the opposite sex is a normal human behavior, but if this behavior is not letting you concentrate in your routine and the depressive symptoms that you have could be multi-factorial ,since you have realized that it is a problem behavior, you should be consulting a psychiatrist at the earliest.