Hi
Welcome and thanks for posting.
It reads very much to me like your partner is addicted to them unfortunately. This is because co codamaol contains codeine, which is highly addictive as its an opiate. It can make you sleepy, and also lethargic.
The vomiting may be where he has run out and gone into withdrawal, it’s hard to say really.
Sadly some doctors do write prescription after prescription.
My suggestions are that he contacts the GP and has a tapering plan sorted out ASAP as this will only end up one way. Its also likely that if he stops, then he is going to feel rotten due to the amount he’s been taking over time. That’s why a taper plan is essential.
I have been through codeine addiction myself, let me know if there is anything I can help with and keep posting