Sudden Change In Behaviour Of My Lovie

Hi to all e experts here,
i went on holiday last week n brought my lovie to e birdshop for 4 days. ever since e day i brought her back frm e birdshop, her behaviour n attitude all changed. She used to be super playful n can run round my house as of no one business but now she became timid n avoids me when i go near it. Besides that, she tends to sleep very often esp in e morning n tis made me even more worried. i oso noticed tat its dropping has tiny bubbles n in milky form. issit a sign of an illness.. my lovie has been laying eggs for e past 3 months but tis month it has not lay.. usually its ard the middle of e month.. i did feed her eggshell n calcium block but she is very picky n refuse to eat.. despite of tat, i still feed her everyday..
the birdseller oso help me to trim its beak cos she will bite veri hard during e period when she's gg lay egg. Can someone pls give me advice cos im veri worried now.