Only two more Sundays to go... try and stick it out if you can. If you decide to pull out of the placement, all your efforts so far will go to waste, and you'll have to repeat the placement, which will mean you end up graduating later and not starting your NQT year until January (or later). It sounds like you are doing ok on your placement despite finding it tough, so it really makes sense to see it through and have it over and done with. Rather than thinking of it as 'complaining' about your mentor, think of it as giving your university some constructive feedback on her. Emphasise that she has been helpful in some ways, but that some of her comments have unhelpful to the point of making you doubt your ability to teach. Give examples so the university mentor can judge for herself whether you are being reasonable. I wouldn't mention your dad's and grandad's illnesses in a conversation about your mentor, as if your mentor's comments are unreasonable then they would unreasonable be regardless of your personal circumstances, and bringing personal circumstances into it may cloud the issue at hand - which is that your mentor is not providing the support she should be. You wouldn't want other students to suffer, which is why it is important to say something to your university, so that they can make the decision to retrain your mentor, not to sendother students to that school, etc.