plz help im going mad

my girlfriend txts other lad which i was not bothered about but i found a txt on her phone flirting with another lad she were saying things such as she was not with me. when i confronted her about it she just gave me some bullshit. i would never normally go as far as checking her phome but she has been giving me reasons to do so latley so i checked but anyway she fed me a load of bullshit an stupid me believed it. so next thing that happens now she is leading lads on facebook as well i didnt like it an asked her why she doing it an she just said windin them up so i thought fair enough as long as it dont go any further than that but she were willing to meet them an it upset me

please somebody tell me my reaction to these situations are normal im actually thinking its all my fault. she started doing all this randomly.

She is an attention whore! Dude she is having what they call emotional affairs. And even though there's no sexual contact, it's still cheating. Grow some balls and dump her sorry ass.

Of course you're normal! It's no fault of yours. It doesn't seem like she's taking you seriously either. Talk her out of it or call it off.

Ditch the BITCH.