I need serious help !!! My girlfriend is a terrible and ambitious liar

I need serious help !!! My girlfriend is a terrible and ambitious liar . She tells lies for a living and never get caught . The worst is that she can die by her lies . I would not deny not knowing she is a lier, but I felt it was the normal small small lies we tell.
Not until one day I had a business trip in Abuja but did not want her to go with me because of my boss is a womanizer and will chase her . So I lied to her that i was just going to uyo to see my bro, which she told me that she will be going Aba for her friends wedding . We both agreed and made love .
After my meeting in Abuja, my boss suggested we hang out with few friends and so many girls every where , I agreed and we went clubbing in abj. I could not concentrate because my gal was not picking her call, so I decided to step into the rest room to go continue the dialing since it was becoming embarrassing and my boss was noticing me with my phone,Getting to the door of the rest room, cause it was the same door that leads to the rest room , male left, female right .

So I met my girl friend entering the rest room , I was shocked and dragged her by her hands but she screamed that I should leave her alone she is not Sharon , I could not believe my eyes , when she pushed me away and ran to the man sited by the vip, I rushed to her and was looking at her like a fool and dialing her no but this time it was switched off , I was just standing gazing at her in surprise as she was also looking at me .

As I went to drag her again , the man she was sited with called the bouncers to drag me out of the club .
I almost lost my job, cause my boss was so embarrassed . I continued calling her no but still switched off . I did not sleep all through the night , I was just fighting with my imagination and trying to be sure I was not blind .
The next morning I took the 10. O’clock flight straight back to Calabar , rushed to her house and found her cooking in the kitchen , she rushed and hugged me , it was a different hair she was wearing and I could not just place anything , so I told her that I saw her carbon copy in club in Abuja , then she screamed (Abuja) baby I taught u said uyo,

so I quickly corrected myself because her facial expression was very convincing .
We talked about it and joked it away . I proposed to her , and we where working on our marriage . I was in her house that faithful day flipping through wedding ovation while she was cooking in the kitchen . When I found a picture of that same gal I saw in the club . Exactly her and the man , that same spot , that chair , and I was so shocked , I was just looking at the pic and looking at her from the kitchen , when i could no longer hold it again , I had to get up to slap her, and showed her the picture . Guess what ? My girlfriend lied that she was a twin , the girl in the pic was her twin sister . I did not know when I hit her again , but she was swearing with her life , that I can call her mum and ask . I asked her why she did not tell me all these while , and she said her twin contacted HIV and her parents disowned her so she is a busy prostitute now . I asked her how she got the pic , the she said they met in Aba and she took it . The only thing that came out of my mouth was (lioness) .
I walked out of her house that day and we have not spoken , she has been begging but I can’t deal .
My question now is , do I investigate. If she really has a twin ?

Or should I just let her go ?

Am so scared of wasting my time at the end .