Help with baby hoody please?

I have knitted all the bits and sewn them together, was all looking good til it came to the hood!
The hood looked fine before I sewed it on, but now it’s sewn on, the ‘face-hole’ (you know what I mean!) is too small and tight. Other than taking it off and knitting a new hood (and risk the same thing happening), I can’t think of any way to resolve this. Also not sure why it’s happened in the first place - I can see from markings on the pattern that I’ve obviously knitted this item before and it must have worked then…
Any advice?

Maybe you used a different type of yarn or needle that gave you a different gauge. Since it’s worked separately and sewn on, I think you’ll have to redo the hood; use more stitches or rows, whichever will give you a larger opening.

Before you take it out (and it sounds like this is what you’ll need to do), measusre the sts/inch that you have so that you’ll be able to calculate how many more sts you need to cast on for the re-knit.

Hi - same wool, same needles, followed the pattern exactly.

I think you’re right, I’m just going to have to start again and make it bigger! Sigh…

It may be that your tension changed from when you knit it before, that can happen.