NEED ADVICE 😭

I have been with my bf for 8 months now we reconnected after 10 yrs so we have history. He has a tendency to get depressed and turn off his phone. He has children from previous relationship and we are planning to get married and conceive. My concern is that he gets depressed due to being in between jobs and the demands of everyday life. I have been by his side I have been encouraging him and it breaks my heart because I don’t know what else to do when he gets like this. It’s concerning to me that he can shut down and pretty much say forget everyone and everything. I don’t want to walk away I just don’t know what else to do. I don’t think it’s good that he completely turns off his phone but who am I to tell a person how to cope when they feel so overwhelmed. 😢😢