Need help please

So I caught my partner out on a lie the other day and it's eating me up.
Last Saturday, we were supposed to go out for dinner or just hang out .. As I asked her Friday night what we could do Saturday.
Anyways she msgs me Saturday day and saids her work friend is Upset she is going to her friends house for dinner and drinks ( mind you I have Been really depressed since my cat passing.. 10.5 years I had him for.) so she didn't invite me .. She just bailed on me and left me at home alone.
She didn't speak to me for 16 hours , I was upset she bailed, and the next day when I spoke to her I asked her what she did and when she got home. She said she got home at 11pm and went to bed.
Friday just gone someone told me she went out clubbing with her friend and they were meeting people out. So I called her and I said what did you do Saturday last week .. After dinner.
She said " I went for dinner and went home" I said tell me the truth did you go out .. She then said " aw I don't rememeber.. Maybe " .. I said don't bullshit me tell me the truth.. Did you or did you not go out .. She said " I can't rmember " anyways she lied straight to my face .. I was so upset and Hyperventalating .. I ignored all her ten million messages and calls for a whole day.
Today was the first time I have spoken to her since Friday. 
She then goes and tells me she didnt tell me cause she didn't want me to be mad... UMMMMMMMM SHE BAILED ON ME AND LEFT ME AT HOME BY MYSELF WHILE SHE WENT OUT BEHIND MY BACK. Am I in the wrong ?? Seriously ??