You can't use 'squeak' or 'squeeze' on their own in that context. You have to use them with 'in' - and these are somewhat idiomatic uses. I find it rather odd that neither of the previous answerers are aware of this use.
I just squeaked in, or I just squeezed in are, as you suggest, quite similar. 'Squeaked' would be more when you just did something in time -e.g. I had to get my application in by 5, and I only just squeaked in.
'Squeezed' would be more if you had to fit in - e.g. I only just squeezed into the packed room. It could also be used for other things, such as 'I only just squeezed mum's gift into my bag' or 'the doctor has rearranged his schedule, and he can squeeze you in at 3:15'.