Lying daughter in a toxic relationship

I honestly cannot believe i am writing this but I am in desperate need of help.
My daughter 13 has had a boyfriend for the past 3 or 4 months. The relationship started off with her lying and denying she had a boyfriend and has only got much worse from there.
Her boyfriend is very toxic and the kid at school who walks around alone (until he found her) he has everyone fooled that he is a shy kid.
I say toxic due to his behavior around others and the conversations between them both. (My daughter is also not a hundred percent innocent, i know that)
Messages between them include things like-
Im going to stab myself because im a piece of shit , im weak. (Whilst my daughter was having friends over and not paying him attention)
Why would she break your phone Charger? She is an ant and i want to stomp on her (my daughters friend broke her phone charger and this was his reaction)
Even more concerning was that he claimed to have sent pictures of his manhood to a friend as payment for his friend helping create a video for my daughter. My daughters response was Wtf?! However she didnt react or tell anyone.This concerns me.
(I sent this information to his parents)
When i tried to be supportive and allowed him to join us for a night out during the school holidays he did not say anything all night, even to my daughter, instead he positioned himself as far away as possible in the corner and used hand gestures to encourage my daughter to remain with him. (Isolating her from friends and family)
There are alot more messages however they are abit TMI.
I have had numerous conversations with my daughter about how relationships are meant to be fun not secret.
Boyfriend is clearly struggling due to his past trauma and ive shown how trauma affects your brain etc.
She has told me they are no longer “dating “ however today i found her at the bus stop with him.
How can i get her to see shes better off without him / stop her from seeing him when they are at school together and i cant be there?
( i have her booked in for therapy in a couple of weeks)