Hi Wintye, you have come to the right place. Mumsnet is a wonderful source of advice and support. I and many many other mums here have known the desolation of PND, so you can always talk to us.
I don't know how to do links either, but hope someone clever will make links for you to some of the very helpful threads that already exist for this topic.
You will get over PND, and you will feel better. You are a good mum. I don't think there are many people who do not shout at their children once in a while. I do it a lot myself, but they are not cowering in the corner, they're still always hassling me about something! They have managed to survive to the ages of 14, 11 and 3.
I find caring for one child under five an exhausting proposition, with two under 2 I am not surprised you struggle to get through the day. You will need to let some things go, you are not superhuman. Before you know it they will be at nursery age and you will be able to get back to your normal standards.
And of course you should accept help. It won't help your family very much if you are ill or stressed out, will it? Take a little time for yourself so that you will be a better mum when you are caring for them.
If you had flu or a broken arm you would accept help. PND is an illness too and so don't hesitate to ask for help.
You haven't mentioned your partner/husband. Is he supportive?