Hi Sma1234,
I believe that people can change if they want to, and with the right support in place.
I appreciate that you want to help him, and be there for him through a difficult time. That said, the best way that you can support him is by making sure that YOU are taking really good care of yourself.
Being a caregiver can cause a lot of stress and worry, so I would not only recommend your guy go get help, but I would encourage you to get some support at the same time.
Maybe if you went to get some help, he would see there is nothing wrong with getting help. In my own life, I have found the best way to help those I love is by leading the way with my own actions. My guy would not get help until months after I started T. He saw how much going to therapy helped me, and then he finally took that step.