Great question and great description! I'll throw in my 2 cents, though I'm sure others will have helpful perspectives on this.

When you say that "no matter how hard I concentrate, my sense of self, remembrance, what I'm supposed to doing, blinks in and out" that definitely sounds like insight. Anytime things are blinking in and out (impermanence), the felt sense of self is coming and going (no-self), or the unsatisfactory nature of these changes are being noticed etc. there is definitely insight into the 3 characteristics happening. In particular, and as you mention at the end of your post, you seem to be describing insight into the impermanent and selfless nature of phenomenal reality.
If you're aim is to wake up, then it definitely sounds like you are on the right track. And personally, I wouldn't worry too much about the concentration, as it sounds like you are practicing just fine.
Best,
-Vince H.