SO thinks I’m emotionally blackmailing him 😞

I don’t want to make this too long but basically I’ve had depression for about 10 months now, and my SO is the only one that knows about it, apart from my GP that diagnosed me (I don’t have any friends I can talk to about this, and as for family I just don’t want to burden them or upset them). I will say that I’m not someone that feels down and depressed every day, I kind of just have these breakdowns 1-2 times a month where a whole lot of things build up over that time and it all just hits me all at once, and then after a week or so it will pass and I think I’m back to normal, until it hits me again. But anyway, whenever I have these breakdowns I always try to reach out to my partner for support and he can see that I’m clearly upset but all he does is either leave, tell me I’m being childish, ignores me, and he will always accuse me of emotional blackmail 😞 and it hurts me so much that he thinks that I do all this just to get to him. I’m really embarrassed to say this, but I do cut myself when I go through these breakdowns and again, he thinks I do it just to make him feel bad and emotionally blackmail him, or he tells me I need to grow up 😞

I don’t know what to do anymore, I hate feeling like this, and I hate that the one person that I need to make me feel better and to be there for me, thinks that this is basically all an act that I do to make him feel bad.

Ps. I’m also 32 weeks pregnant, so all the hormones are making things a lot worse and I really don’t want to have these feelings when my baby is here, I want baby to be happy 😞