Postpartum depression or bipolar triggered by childbirth?

My partner seems to think I am bipolar. A little back story, my daughter is 10 weeks old and since her birth I have been extremely depressed. I started medication 8 weeks ago and I’ve since had it increased. I am working with my health visitor and a perinatal mental health nurse. I haven’t bonded with my baby, every night I wanted to run away or overdose. I even self harmed a little but it didn’t do much for me so haven’t done it in a while. I’ve basically been living in my bed hating life. Today I woke up feeling like a new person, suddenly I have energy. I organised the cupboards and have spent hours cleaning and tidying already today. I don’t feel overly happy but I don’t feel depressed. All of my problems are still there but they don’t seem to be affecting my mood today. I meet with my mental health nurse tomorrow so I’ll obviously speak to her about how I am feeling now and she is the expert. My thinking is my medication has finally started to kick in and I’m just having a good day. Thoughts? Or experiences?