Hugs hun, nothing worse than sleep deprivation and the strain of constant feeding.
DS3 suffered a bad bout of colic when he was about 3 weeks old. I started taking him to a good paediatric chiropracter and she's worked wonders.

And this isn't so much advice as in letting you know what also helped my DS3 - sleeping on his tummy. Back when he was unsettled, he'd go to sleep on his tummy really easily and sleep for hours. DS3 did/does have incredibly good neck and head control for a little tacker though, and while I initially had reservations about sleeping him on his tummy, I'm much more comfortable with it now - though I do regularly check on him. I only tummy sleep DS3 during the day and when he's really unsettled. For the most part, he sleeps on his back now. Many others will be horrified by the idea of sleeping a small bub on their tummy, but I honestly think some bubs are born to tummy sleep. The chiro also said if they are windy bubs, the pressure on their tummy makes them feel better.

Hope you get a few hours sleep very soon, xx