I am confused. Most of time. suggest me.

Hello doctors, I am 24 years old, male. Since a month I'm facing a problem that is head ache, my mind is almost blank, I can't make decisions and I can't think. I feel my mind is blocked. I am stammering when I am talking to anyone. I can't recollect names of people. I'm struggling to learn new things. My intelligence level is low. There is a region in my brain i.e central part whenever I put effort to learn or think it pains me in the central region. Struggling to say proper words(it never used to happen before!) let me be more precise about me. I am on Bp tabs betacap tr40 and am taking this tab since 4 months earlier I used to take Met xl 12. 5 untill dec'16. Even I used to take nexito10 mg, but discontinued 5 months ago. Is there any damage in my hippocampus. I used to smoke untill Nov'16. I quit this 4 yrs old habit. I find difficulty in retrieving information from brain and there is a mid portion in my brain which pains wen i put effort. I feel depressed most of time. Suggest me.