Re: colic and comfort nursing - ahh!
Ladybug was very much like this. The Moby was a life saver in the evenings. I also found out she had reflux and that all the comfort nursing was making it worse. Maybe see if her being upright as a PP said will help. I finally learned to sleep sitting up with her on my chest. Also, gentle bouncing on the birth ball seemed to work much better for her than a rocking chair (though it was much less relaxing for me!).
It got so much better when she started solids. I started her at 4 months and by 6 months she started sleeping for several hours at a time.