I want to save this

Our relationship has been mainly happy, for 4 yrs now he has helped me raise my other 3 children and now we have our own little one who is 6mths old. Things started to change a few years ago he says. He thinks I tell him what to do too much, I feel I have to push him along sometimes to be an “adult”. I hate that I have to ask for his help with almost anything. He doesnt just do things to help unless its hang with the kids. dishes. washing. house stuff like lawns or even planning for the future, looking for a home together, talking about what our plans are for our life etc. He hasnt offered to go shopping for christmas yet and with 4 kids altogether, a bad back at the moment and not much time without the kids to actually shop for them, I feel alone in this like a single mum still. I have bought absolutely everything this year. He blames it all on depression and says its my fault hes unhappy so after hearing this so often and him becoming less affectionate over time I have realised how much we have grown apart and its sad, because I love him, hes a good dad, but theres no kisses or cuddles and he doesnt stay up until I go to bed. ... we have sex still but I dont feel connected to him like before, I feel like I may have started to believe that im making him unhappy and Im just giving up without truly acknowledging it yet as im so busy with my kids. I feel alone, unattractive and his depression is now making me depressed. the happiest time of my life, with a.little baby is tainted by not being close to my partner or truley sharing the happiness together, he wont let me enjoy this time and its killing me. I dont eat properly or put myself first.anyway and I feel like im fading away, I dont even know how to fix this anymore, do we need time apart for him to wake up？