Can somone help me out here ?

My girlfriend is amazing , Never thought a girl like her would like me . Kinda makes me wonder if its all a game . I ask her what she sees in me and she tells me . Anyways Tonight she texts me saying im in a crappy mood , I'll ttyl . I text her 2 hours later and ask her is she ok , she says yea and then i start to wonder again if she really likes me or is it just a game . She asks about our female friend and then flips when i ask her , do you really want me ? She then accuses me of wanting our female friend and i asure her that i don't and i don't . She then says im insecure im sorry . What is up with this ?