Hi Dasein! I remember you... I don't know if you remember me... philforum.
Asking "who am I?" and experiencing the opposites overlapping is definitely a recipe for new ground. Funny you use the word "ground." Check out Meister Eckhart sometime.
Dasein means "being in the world." It's one experience. From the intellect's point of view it's two sides to one coin. But the intellect will find experience of the whole coin inadmissible. What actually keeps a person from experiencing it is emotional anchoring to one side of the coin. That's just an aspect of living an earthly life. There's nothing wrong with it... it's the mechanics of the amazing little play we got going on here.
Yea, you're not alone... many of the characters in the play are like you.
For what it's worth... feel the sensation of your body. Bring your focus out of your head down toward your chest. Notice the sensation at your solar plexus as you breathe... that's where your ribs meet your abdomen... it's pretty cool.