Need advice---Worried about Morgan

This just started probably Sunday or Monday this week but Morgan's temperment has changed quite suddenly and I am concerned something is wrong but have no idea what it could be.  She has all of a sudden become inconsolable (sp?) whether it be while in the middle of playing, someone holding her (including me or daddy), or whatever.  Nothing seems to stem her crying and screaming (sometimes very shrill screaming), she just starts a fit!  Now sometimes I could maybe attribute it to being tired because I can note that she's been awake for a couple hours or so (she usually sleeps after being awake for around two or three hours).  However, it is getting to the point where it is not that likely she is sleepy that often.

Also, when I try to get her to nap during the day, she is quite difficult to put down because of the fits she is throwing.  I often have to bundle her in a blanket, rock and bounce her in my arms, "shhh" her a little, hold her pacifier in her mouth, and hold her tightly against me because her arms and legs are thrashing too much for her to calm down.  This usually only lasts a minute or two before she starts to calm and falls asleep.

I also, of course, try feeding her when she starts these fits but that is never what she wants whether I try a bottle of breastmilk or from the breast itself.  She just screams as the nipple is near/in her mouth and never takes hold of it.

Possibly related to this, she did not gain weight from Feb. 14th - Feb. 21st (I go to a breastfeeding class to weigh her each week).  This is quite unusual for her because she has been gaining between 4 and 8 ounces each week which is what my doctor recommends for babies her age (0-3 months).  She is at about the 75th percentile for weight so I'm not concerned she's not healthy, just that she didn't gain anything.

I try to think of what my diet might entail that is upsetting her too as she tends to have quite loud and full bowel movements (going on for probably 5 or 6 weeks now).  I eliminated coffee for about 4 days thinking maybe it was having a laxative affect on her but it did not help.  I have not introduced any new foods into my diet this past week (or really since I had her) and I don't eat spicy foods nor does she get any formula.

I thought it might be teething since she's been drooling since 9 weeks old (she's almost 11 weeks) and sucking on her hand/thumb more often but not mouthing toys yet.  I tried giving her 1.25 mL of Tylenol one night (her dosage is 1.7mL) to see if that was why she was fussing but still an hour or two later, she had another episode.

I feel like there is just nothing to pinpoint her frustrations but as her mommy and primary caregiver, I feel like something isn't right.  Babies nearing 12 weeks are supposed to be easing on colic symptoms, not getting worse, and I would never say she had colic in the first place.  Today I started tracking her naps, BMs, and eating habits again so I can call the doctor's office on Monday but I just don't know what they will say as she doesn't have fevers or vomiting or really much gas at all.  

Any advice or ideas on why she might be getting so upset?  Love you guys!