Napping Issues - Down to Only One 30-minute Nap?

DD used to take 2 naps a day, totaling about 3 hours.  Then she started sleeping in later about 2 weeks ago, so we were only putting her down for 1 nap, totaling about 1.25 hours.  All of a sudden, she is back to waking up earlier than before in the morning and refusing to sleep for more than 30 minutes the ENTIRE day.  She's obviously exhausted, but when we try to get her to nap, she'll fall asleep really quickly on me or DH but screams the second we try to put her down.  I'm a stay-at-home mom, so I don't know why separation anxiety would be kicking in.  Is that what this is?  We've also started trying to wean her off bottles recently.  She's drinking the same amount of milk but with fewer bottles.  She's teething, but Tylenol and Orajel have both failed to help her sleep and she's never had too many issues with teething before.  Please help!  I know it can't be good for her to only sleep 11 hours a day!