PND? Feeling down and overwhelmed

I’m not sure if these are normal feelings or something to be worried about. I knew having a baby would be stressful, hard work and tiring but I’m feeling incredibly overwhelmed. I feel ashamed to feel/think this way as I have a beautiful perfect little boy but I find looking after him really hard and worried that this is life from now on. He’s never slept well at night and for the past 4/5 weeks we’ve been in sleep regression (what we think is happening anyway) and I’m exhausted from getting up nearly every hour during the night plus he’s teething and in pain during the day. People keep saying things will get better but I’m struggling to see the light at the end.

Any advice welcome. Could this be PND? Or normal feelings?

Thanks x