Hi - Just wanted to add my virtual support. Firstly, congratulations!
Maybe my recent experience will help? Our baby came 5 weeks ago, it was my first and my partners third child.
We have had some absolutely steaming rows about things - very quietly as we can't yell at each other because of the baby! It boils down to 2 basic things 1, sheer exhaustion and irritability 2, the fact that each persons expectations are different.
Our main problem was that he was used to raising babies very bottle-fed, regimented schedule, leaving to cry... etc. because of his ex-Mrs. I consider the baby to be a bit young for this stuff - he's a free spirit! I BF, which is very time consuming and means partner can't feed him which he misses.
I would say if you can put aside some time, difficult I know, and just each get your expectations out in the open and both come up with solutions rather than problems you'll get a better idea of how to proceed. This worked for us, especially as I used the sort of language he uses at work to discuss our issues.
I think people have an idea of what it will be like when the baby gets here and the reality is a shock.
I don't think it necessarily means your DP is a villain because he's criticising you. Its probably a response to the mayhem but he should understand that its not helpful and it has to stop.
Definately close the door to visitors, not unless they are also going to spend time with Mr Mop and Mrs Iron...
Oh, and you have to laugh a lot - specially about poo and sick and stuff. Smile and breathe.