I think my partner has postpartum depression please help

so I'm 17 and my girlfriend is 21. 1 month and 7 days ago we had our first child. His name is Theodore and he's the most beautiful little boy. We both love him so much but she hates being a parent so much. I really don't know what to do shes so depressed about it and I'm terrified i don't want to lose the love of my life but I don't know how to help and she refuses to let me make an appointment with our doctor. sometimes it's like shes not even there and I'm just alone I'm trying to be the best dad and boyfriend I can be but I'm exhausted I need help. I really need advice from moms and dads who have been through this before I'm so petrified I'll lose her shes helped me throughso much. I lost my dad to suicide battled addiction for multiple years been molested survived 4 suicide attempts and she saved me and has brought me out of my depression after all of that I cant lose her I need her and so does our little boy somebody please help us (sorry for the bad writing and getting off topic I'm just so scared)(picture is of our boy and me)