well back to the op, i had a mate who's gf was bonkers.real mood swinging nutcase and also a fitty!suprise,suprise she was a bit of a bertie basset to!
Best bet is stay away.its the way she's wired up plus its def the coke increasing her nuttieness.dont take it personally, and despite the ribbing youre getting on here you are a decent bloke cos you care about a long term mate…but if your mate is doing as much coke as her, well youde best move away.if hes not, tell him to move on for his own good.