My partner attempted suicide.

Last night my partner overdosed on prescription meds in hope to never wake back up. He called me in tears saying he was so sorry and he loved me and suddenly thudded and stopped talking so I freaked out and called the ambulance and met them at his house, then spent the next few hours with him in hospital until he was discharged. I'm having trouble understanding why he felt this way and what caused it, he doesn't tend to talk about his feelings and bottle them up. Please does anybody have any advice for me please? Has anyone been in this boat? I want to help him but I don't really know how 😭 any advice or comments is great, Thankyou xo