Stag do

Ok, so my SO is going on his stag do next weekend. Booze cruise to Amsterdam with 20 of his mates. My fiance used to be a massive player but hes never physically cheated on me but in the starting months of our relationship he was sexting a lot of girls. Deep down I know he won't cheat on me while he's away, but I have such low self esteem that I dont think I'm pretty enough for him and I'm scared that he'll go and see someone better looking and be tempted to go back to his old ways. I'm even scared he gets a lapdance and the woman turns him on!!