Mood crash? Is that a thing?

Not sure whether to post this in pregnancy or mental health. Could be due to either honestly.

So I have depression and anxiety and I'm 33 weeks pregnant. I have gone to a therapist for the depression and anxiety but not recently and honestly probably not enough. I was going to start up again buuuut COVID19 got in the way. Basically I'm saying I haven't heard of this but it could be related to any of those things I assume. 🤷

So I just had a very sharp 'mood crash' I guess I'd call it. Like I've had a nice day. Went for a long walk with my husband and then came home and had a nice lunch. Nothing negative at all. But then I was sitting down after lunch and I had the overwhelming urdge to cry and just felt sad. Which I know is depression but it happened in the matter of seconds. Like I was laughing and then all of a sudden I was just so sad.

Depression for me is just a constant, not a sudden thing. Anxiety can but sudden but useually it's triggered by something for me. And I have not been a moody pregnant person (aside from the things I normally struggle with) at all so I don't know what a mood swings feels like.

Maybe this is dumb. But does anyone know what I'm talking about? I felt like a SIM whose player was cheating and moved all their moods down. It was so sudden and I'm frustrated because it feels more intense than my normal depression.