Just wanted to mention that I've tried a ton of different things to ground myself. Meditation helps. What I found to work best, surprisingly, is weight lifting. I just use free weights. I don't know why exactly- maybe because you're so focused on your breathing and the movements and just on the here and now, and maybe because there's a bit of pain to bring you back to reality? Not sure, but this is the most effective thing I've found so far.