I know there is postnatal depression, but is there antenatal depression too??? I am sooo exhausted, I'm emotional and I keep crying over nothing

I've been like this for the last 5-6 weeks. It's gotten so bad I asked my midwife to refer me the maternal mental health people! They sent a really lovely nurse lady around to my house to talk to me and it helped me feel a little bit better I guess but not much. I've had problems with depression before and been on medication/seen counselors so I figured I should take the help that's available because I don't want to still be feeling this way once baby arrives, and whether it ends up being because of hormones or low iron or whatever else it could be, I don't want it to have any effect on me bonding with my daughter etc. Does anyone have any advice or is anyone else going through this too? Should I just hope it goes away?