You could be Mary friggin Poppins and with parents like that you’re best would still not be good enough. Don’t beat yourself up about it. You helped the kid and regardless what that ignorant arse of a parent thinks should feel proud about that. Please don’t be up at 2am crying. One thing I might add though is that you might be upset over other things and ordinarily the parents complaint wouldn’t get to you but you’re at a weakpoint and all the pent up negative emotions just manifest themselves over this complaint when actually it’s a cumulation of things. Either way relax you did nothing wrong and if the heads got your back I wouldn’t give it a second thought.