9 week old not sleeping

So our little one has never been the most amazing sleeper but still used to do 3 hours at a time most nights, the most shes done is 5. 5 hours straight.

Over the last week its got worse and worse.. She just will not sleep in her crib and is a nightmare to just get to sleep to start with. When we finally get her to sleep she'll last about an hour and wake up to do the whole thing again.

I have no idea what has changed, does anyone else have any experience of sleep regression or trouble at this age? Any advice would be great, starting to feel like she will be like this forever!