Hey OP. If you have a history of depression has your midwife or gp referred you to your local perinatal mental health team? They usually look after women who are pregnant with mental health problems and up until a year after the birth of the baby. Even if you are not unwell at the moment and don't require a caseworker from the mental health team, perhaps you can be made known to them if you do require any advice or support after your baby arrives?
My baby is four months old. I have a history of mental health problems and was on the radar of the PN mental health team whilst I was pregnant, as I take medication that meant extra monitoring for the baby during the pregnancy and delivery. I was well during pregnancy. I stayed on their caseload afterwards which was good because sadly I have developed PND and have had some trauma from the birth. The mental health team have been an amazing source of support though and have really helped me and my husband cope.
Even with these difficulties I am managing. Something I would recommend is trying to keep to a routine for yourself as best you can, however that might look for you. For me I made sure I showered daily and had enough water to drink and food prepared which I could eat quickly with my hands and didn't need heating.
Before the baby came I made a list of my early warning signs for a mental health episode coming on and what can often trigger them and I shared this in a document with my husband as well as coping strategies I use. So, he could suggest to me if I was feeling really down to take a short 15 minute walk or do some mindfulness or deep breathing exercises.
If your partner isn't that wise to mental health then this approach could really help.
That's my advice for preparing for the postpartum journey from a mental health perspective. Good luck, you'll be great x