Emergency services found the student hanging out of a bedroom window at the family home in Haywards Heath, bleeding from the groin.
The man is thought to have had his penis sewn back on at University College Hospital. A friend of the family told the Mirror:
He is normally a lovely lad and very bright. But unfortunately, he had started dabbling in drugs.
He had come home from university for Christmas. It looks like he took mephedrone and completely flipped out attacking his mum and then himself.