Do I let the narc see my boy on his birthday after I have cancelled all visitation until I go through solicitor?

I've got strong I said no more! I've blocked on everything possible, ive got my friend to email narc saying contact is cancelled as we need mediation support to sort out visitation for what's best for our babies, as at the minute it's all about what's best for him and it does not benefit babies at all!

So got strong, feel a huge weight has been lifted apart from this guilt feeling that it's my boys 6th birthday next Wednesday what do I do? Have I to let him see him? But I will be goin back on what I have said? My little boy has learning difficulties and would not understand if his dad was not there on his birthday as it wouldn't enter his head. But could narc use it against me in court? Or am I being unreasonble I feel so horrible but if he was to come he would torture me with his bad vibes I can't bring myself to be around him for even a second! Also if he did see him and was to visit my little boy would then start on repeat asking for his dad to take him out. Where as at the moment he hasn't asked about him (out of sight out of mind so far) please help I do not know what to do for best? Thank you xxx