I'm struggling with this as well. I know what you mean about always looking for signs in other people to see if they might be someone who will hurt me. For me it's especially prevalent when I'm around men in authority. Even when I know them really well and rationally know they are safe I still have a hard time. Things like understanding what they are saying, talking/speaking up to them, or even getting jokes. For a long time I thought I was just stupid. But then after talking things over with my husband I realized it's because I'm distracted with analyzing them for any possibility that they might hurt me.

I also understand your analogy for putting out a fire with an eye-dropper. That's a huge part of why I dislike DBT so much. It's helpful with the usual depression and anxiety but it does absolutely nothing for me when it comes to PTSD. My husband and I have discovered that ice packs help me a lot. I don't even wrap them like you're supposed to. I just hold that freezing thing right on my chest, the skin if at all possible. It starts to hurt after a bit but I find it really grounding. Especially because I start getting overheated and I feel like my clothes are clinging to me. I also start feeling trapped and all of this creates a worsening spiral.

The hardest part that I haven't been able to figure out is how to cope with hyperarousal out in public. I've tried the sensory grounding technique where you identify what you see, hear, feel, smell, and taste. If I'm able to, I usually go find the restroom, go into a stall, shut my eyes, plug my ears and try to focus on my breathing. It gets really hard to focus sometimes. Someone once suggested keeping sour candy with you. It can add a sensory shock. Aromatherapy doesn't help me too much but it does for some people.