Welcome Shelby to the forum. Thanks for making your your first post.
This a kind and supportive place. I can understand that the past few months have been ver difficult for you both. It is good your partner has gone to the doctor and has spoken to you about his feelings.
Sometimes when a person is depressed they may be very confused about their emotions and feel they are not worthy of love from others. He may feel he is not capable of loving anyone.
Depression is a cruel illness and deceive you into thinking you have no value and that you are a burden to your loved one.
Everyone is different so I would not give advice but keep on being supportive , patient and understand your partner may be quite confused and troubled for some time.
Also you need to take care of yourself as it ican be exhausting living with someone with depression.
There have been other threads on this theme so if you type in depressed husband/partner into the search engine on the top right hand side of page you will find threads that may help you.
Feel free to post here as much as you want to.