sleep, or lack thereof

from the beginning, a has always been a good sleeper for us.  as a newborn, yes she was up every 3 hours to eat, but between those feedings?  it was sleep city.  the hospital was actually the roughest part as even though we were supplementing with formula at the time the nursery would always kick her back to us when she was hungry fussy. and we hated keeping her in the cage basket thing that they provided so jim and i were always up.  but once we got home it was smooth sailing.

so currently, little a is at 4.5 months and i am a little bit lost.  i have been loosely following healthy sleep habits, happy child but with my type a personality it was almost doing more harm than good as i was forcing her into a schedule at too young of an age and disrupting the good thing that she naturally had going.  but now... well now we are all over the map.  her bedtime is consistent, 7 pm.  however, recently at 7:45 she has been waking up INCONSOLABLE until i go in and nurse her.  jim and i do practice some CIO methods but we do have our limits, and i am just not able to let 45 minutes of inconsolable crying go by if i can fix it.  20 minutes of crying and then asleep for 8 hours?  that i can do.  but after nursing at 7:45 she then promptly drifts to sleep and i don't hear from her until a feeding.

at three months, she was doing great.  bedtime was between 9-10, one feeding at 4 and then up for the day around 8.

now we are all over the place, sometimes she is up as early as 1 and then 2x more throughout the night, sometimes she has made it till 4:30 without waking up.

and her nap schedule is just as inconsistent.  she is usually laid down for her nap around 9:30, sometimes she is asleep for an hour, sometimes it's 2.5.  i just don't have any way to plan it.

and i'm not sure what is causing it... her ped's gave us the ok to start cereal... will that help?  is it because she is teething?  is she having nightmares?  or are we causing it by giving in so to speak?  is she going to bed too late (the child is seriously sleepy by 6 but if i lay her down to early will that cause her to wake up early?)?

first time parenting is tough.  and i know we will figure it out and it is winter so we don't have a too many things to get outside for... but it is tough to not have a schedule because the kid is losing her shit every time we leave the house because all the sudden she is tired and i had no way of knowing.  i just want to make sure she is getting the sleep she needs and also start her on a consistent schedule to avoid future problems...