6 months is a recognized growth spurt period so babies will be hungrier around this general period. At this stage they are unable to read the text books so it varies a bit between individuals. This is also the recognised start of teething, although it is also very variable. In my practice we ask the parents about any changes/events that preceded the change in behaviour pattern. This includes teething, illness, immunization and trauma (can be as simple as a toddler being a little boisterous with them). You did mention a cold. Without a full detailed history I can only make broad suggestions. Trial more food/solids (does bub watch you eat? This is a good sign they are ready for solids) I tend to recommend fruits and veges as rice cereal often constipates. Some babies will respond to "controlled crying" or other sleep techniques depending on your beliefs. If this is not for you that is fine. They should respond really quickly if it has only been a short term problem. My instincts tell me this won't be the case for you as sleep is also a daytime issue. We see a lot of bubs like this and get fantastic results. Feel free to send a private message if you would like to ask more questions.