Remember the AA advice: one day at a time. And if you can't make one day, 1 hour at a a time. And if you can't make one hour, 10 minutes at a time.
Big hugs to you. How I remember the stone in my heart. Remember that chutney is NOT YOUR FRIEND.
I am very very suspicious about this counselling. This is his glorious drama, remember he is coming in from the feelgood side, he is getting the admiration and the support and the wonderful orgasms and the heady love, and now he is going to have a stage to set it all out and by the good guy! - and you are the dustbin.
IF you do go (and I hope you don't), just say the word 'narcissist' in a sentence quite quickly on to alert the counsellor (he probably won't even notice).
The thing that has completely scarred me, was his unfeeling cruelty. So it wasn't active malice it was passive; but he did not care how I was feeling, what I thought, whether I hurt. I was a dust ball under his bed.
And I am getting HUGE vibes like this from your not-a-friend. Protect yourself.
Also, talking to the building society is a good idea. You can have mortgage holidays of up to 2 years, can you not? They are very reluctant to foreclose so I hear.