Yes it came from nowhere. I woke up in the middle of the night and felt like I couldn't take a deep breath. Managed to eventually get back to sleep but had worked myself up about it. When I woke up that morning it's the first thing I thought about and I haven't stopped thinking about it since. Before that I'd basically never had a sick day. Had never been anxious or worried about anything and slept like a baby. This has really thrown me. Like I said earlier though I have basically tried everything but the amitriptyline seems to be the only thing that is working. I'm starting to feel normal again and it's just so great to not have that overwhelming feeling that I need to breath deeply constantly. No I've never had head pressure - just pressure in my chest.