Ah I remember feeling just the same with no 2. You have the raging hormones, exhaustion , and probably feel like you've ruined life for ,your 3 year old (you haven't!) On top of that the weather is rubbish and doesn't life anyone's mood.
If it doesn't pass soon, have a chat with your GP or HV in case PND is raising it's head, but also, going from one to two children is a massive difference (I had four close together and the first jump was definitely the worst). You will find new routines when your DH goes back to work and it will get easier.
If you can get out in the fresh air, do, even if it looks grey out. Can you meet up with some other Mums, or pop to a toddler group/baby sensory etc? I found it a sanity saver.
I did develop PND and didn't bond with my second born for quite a few months as a result...I was just so flat and miserable BUT I got help, it passed and eventually having two was awesome fun (then I got pregnant again !)
Hang in there, and don't suffer in silence. Lots and lots of Mums feel the same xx