it's hard to physically and digitally keep them apart if she hasn't yet officially said it's finished. I think he's better than being dangled on this string
What are you talking about ?
You said
She told him she wants it to end yesterday
So how is he being "dangled on a string" ? 
"I want to finish this relationship" is pretty clear, however much it might not be something you want to hear.
^She's at work and he's gone over to her house to drop off his beautiful valentine gifts. Personalised thoughtful things. My heart is breaking for him.
I have to just be here don't I ? He wants to see her mum and tell her to get her daughter to not ditch him^
You really need to make it very clear to him how bad an idea this was, and then be very clear about how he needs to respect someone saying they don't want a relationship to him means they don't want a relationship with him.
Obviously we don't know why he is having counselling and what issues he has with his mental health, but whether he listens to you, his Dad, his counsellor or somebody else, somebody needs to get through to him his behaviour is worrying.