The sense of being in limbo is the worst part about a relationship which ends with no closure. My gf left me out of the blue; ending us by phone. My kids run rings round me too. They're 16 and 11 so there's lots of school pressures (exams etc). While I'm busy attending to them, things are not too bad but the realisation she's gone usually hits randomly and unexpectedly. I'm reduced to tears at least twice most days and she's been gone almost 4 months now.
Letters can help. My computer is littered with them. None of which will ever get sent. And therapy is helping to a degree. But I'm fast coming to the realisation that it's my own stuff holding me back; stopping me from healing. I can choose to let the memory of her mess with my head or I can choose to not let it affect me so hard. Easier said than done because of the myriad of unanswered questions I have. Questions she is never going to answer. But I guess time will do its best to level things out. And in the meantime, I try to enjoy my children because this time with them is precious too. Once it's gone, there's no getting it back again.
I hope you find the strength to get some counselling. You're right. You DO need to be in a strong frame of mind to teach a classroom full of children but it's all about baby steps. One thing at a time else you'll implode from the enormity of it all.
I'm new to PC and people here have been so lovely to me