Well you've accepted the offer now, so you're stuck with it aren't you. There's not much advice anyone can give except:a) start looking for another job - go back to any other applications you made that are still in progressb) start work and keep the money flowing for the sake of your familyc) work your tail off and see how it goesBtw, you have a family, you're joining a graduate scheme, and you're wondering about long hours??? That doesn't bode well for colleagues putting confidence in your judgement or inviting you onto their teams.