Just wondered if anyone was in the same boat. I have found myself very down this pregnancy (27w with second DC, I have a toddler). I already avoid the news and anything a bit dark and sinister (ie have not been watching Black Mirror!!) as bit of self-protection but I'm finding just every day situations a bit much.
Not really sure how to explain it, just find myself overwhelmed with negative thoughts and worries about every single thing. A few examples:
If I start to think about DC's future, Trump, Brexit, North Korea, everything spirals out of control into 'the whole world is awful and my DCs and I will soon be living in a post-apocolyptic nuclear wasteland' 
If anyone says anything about my toddler I immediately take offence.
'Oh he's full of beans today'
Me: 'piss off, being a parent is hard work, just because he's a bit intense doesn't mean he's not wonderful, why don't you F off back to your perfect children'
Obviously I don't say that but I think it and then start to think that I am obviously a terrible shitty parent. I feel like whenever anyone looks at my bump they are thinking I'm far too inadequate a parent to have a second and maybe I should concentrate on not screwing up the first one.
The absolute worst thing is my work. I've always felt a bit lacking in confidence but it's becoming crippling now to the extent that I am not functioning that effectively and have started to think I shouldn't go back after mat leave...
Sorry, this is really just a self-indulgent post but I'm just not my usual cheery glass-half-full-self and my emotions are all over the shop. My thoughts seem impossible to control and just lead me to feel sad and anxious a lot of the time. Is this a pregnancy thing? I really don't remember it from first time!