My mind is not in my control anymore.

Hi, I am having serious mental issues since last 2 years, I have not told this to anyone, although I have researched a lot about it, I think I am losing my mind completely, whenever I wanna do something nice and good my mind kind of talk me out of it, it just goes against it, whenever I am feeling happy, my conscious mind goes against it and at the end makes me sad instantly. It is like my mind is separate entity from my body, never listens to me, always going against, I feel so stressed all the time, I lost my confidence, My mind keeps on thinking all the time, I can't stop it, I can't even sleep, It is effecting my health, my relationships with other people. I get offended very easily, I start hating people even my best friend, I question myself, my decisions. Negative thoughts most of the time, worrying too much over small matters, Headache and sometimes I start sweating even if AC is on. I fear I won't be able to recover my self ever, Please help.