helping a depressed person

so my man has depression. we’ve been together for about 4 months now. it’s the worst it’s ever been but he keeps it bottled up and i had no clue until now. he’s giving up on everything. college, work, me, life. i dont know what to do or how to help him. i beg and beg him to try and see the improvement (a little bit, but some) and to know that things will be okay and to not give up on everything he loves because of this. i just want tips on how to help him better so he doesn’t feel so alone and like he needs to bottle everything. i havent slept at all. i nearly lost him and it’s all because of this horrible mental illness. please, any tips to help him. he’s the most important person to me.