My yorkie isnt feeling very well, any suggestions? ?

my 4 yr old yorkie isnt feeling well, shes not doing much, shes thrown up 3 times, not eating today, and seems to be constipated, she seems to be able to get alittle poop out but its slimy and mushy and really gross. She also "looks" ill, she just isnt right. Ive been told I can give her pepto, shes a healthy 12 lb yorkie (please dont tell me shes over weight, shes the large breed yorkie and not a 5 lb show dog, but she is full blood, not a mix breed) Any suggestions for helping her feel better???