Hi there,
Depressed mum here too
I'll tell you a bit about what I went through that sounds similar to your situation. If you'll bear with me a bit
My daughter nearly lost her life to a staph infection at birth, I felt totally powerless and my depression became major and I started being anxious, I didn't want to take antidepressants as I believed they changed who I was. I progressively went down hill, from a little bad but able to function properly to unable to do the most basic things. My children are my world and I thought trying to be the perfect mum meant being there for their every need, protecting them to the point I could ensure they never suffered as I did (I was raped multiple times as a child). They've always been important but I didn't see myself as important. It's impossible to be a perfect mum, but if you treat yourself as a priority they're learning to treat themselves as a priority, this is not easy when you're in a bad place, but I wish I had known just how much of an impact on my children it was to not value myself. Sorry, I feel like I'm not explaining this well

I cant think of the proper saying but it's something like , you cannot share if your cup is empty

Something like that.
My partner was also unsupportive.
I tell you all this because I implore you to take action now before the depression has a chance to get worse. You can fight it, the sooner the better. A psychiatrist will be able to help with meditationo (i do not recommend a gp, they just don't know what they're doing in regards to depression). You might have already been prescribed something !? I dunno but a second opinion is really really vital. A psychologist may be able to help with talking about stuff. This may be a scary prospect , seeking help, but it's important to look after yourself. Depression makes you feel like no-one cares and all that but it's simply not true. Medication has helped me a lot but it's not the answer for everyone don't get me wrong. Theirs naturopathy, there are other options as well, it's a matter of finding what works for you. I just hope you see that you are worth it and things will get better. I hope I have been of some help to you.
Wishing you well