Sounds like someones body clock is all over the place
Do you co sleep through out the day? Whilst I loved co sleeping (and still do ) I made sure my little darlings had sleeps through the day WITHOUT me so I could get a little breathing space and they didnt smell my milk KWIM.

I had an aweful time with DS2 and found that if I timed his sleeps through the day (meaning waking him) he slept better at night.
It not a nice thing to do but as your little ones clock is like a NB's by the sounds of it...maybe you need to teach Elliot's body clock what day and night is again.

I also found that this was the horror age when solids were starting to be needed...eg fuller tummy at night and just needing that little extra

Your doing a fantastic job...dont doubt yourself....parenthood isnt easy but its the best job in the world