Obsession of being perfect, self-doubt.

I have become very self-critical, and because of that I always tend to seek validation from others, I always try to fit in either by doing something which is beyond my league or by lying. I am like this from past 5 years. And now I have come to a point where I am only thinking of how I can impress others and not doing anything. My mind has got clustered with so many unwanted thoughts and it's never stable. Even I cannot keep track of my thoughts now. I am not able to sleep at nights. I have stopped doing anything. Just sitting ideally and passing my time thinking for those validations. Even now opinions of strangers matters to me alot. I try to impress everyone I meet. I want them to like me. And if I failed at impressing them I immediately start getting anxious and doubting myself alot. And I would cry at nights thinking about this things only. And then I would not stop there I would give my 200% to make the other person like me. I don't know why I am like this. Please help.