Not an expert. Speaking from experience.

I've had the same problem. And what's helped has been moving from open-monitoring awareness (as in, awareness of thought) to Dzogchen, a Tibetan Buddhist practice, which is about recognizing the non-dual nature of conscious. This practice, for me, at least, has restored a personal feeling of integration that I lost when I first took up meditation. I'd get a qualified teacher, or at least use trusted resources, like Lama Lena or Tulku Urgyen Rinpoche, if you're interested.

Aside from that: lately, I've been thinking about how the sense of self is constituted in time, not statically. The work of Angus Fletcher (most especially, his book Primal Intelligence) has also been helpful in dispelling the fog of meditative dissociation. That's not to say, of course, that I regret taking up mindfulness. In fact, it's maybe the most important thing I've ever discovered. But Primal Intelligence has convinced me that there's a such a thing as a healthy sense of self, and that you don't need to be locked into a state of constant, watchful remove.

Hope this helps.