Hopefully you are able to make an appointment for your boyfriend. If the Dr agrees to doing a mental health care plan, there will be a lot of information asked for and questions to be answered. Hopefully your boyfriend can be as honest as possible so he can receive some help.
From my own experience with mental health issues, it is not always easy to admit that I am struggling and have issues. For some misinformed people, depression and anxiety are not classified as "illnesses" but as a weakness. That is not the case at all.
Hopefully your boyfriend can admit that he requires assistance.
How are you coping with the regular changes that seem to appear in your boyfriend? It can be difficult living with a person you love and care for so much and see them struggling.
The Beyond Blue website has helpful information on how you can support people and how you can look after yourself as well. You may find it beneficial to read some of the information.
Wishing you both all the very best.
Cheers from Dools