How can I approach hard conversations with my partner?

We have been dating for years. We have moved in together, then we moved states with each other, and now we live in our dream house with our best friends as roommates. My partner helps me in so many ways and is genuinely a very sweet person. I care about my partner immensely and it hurts me tremendously even thinking about this. I want our relationship to work out.

When my partner is in a bad mood they take it out on me. If I let’s say forget to take out the trash they might make passive aggressive comments about how I don’t do anything (even though I do a lot if not most of the housework) or they might start screaming and throwing things around me. They struggle a lot with their mental health and they’ll have these mood swings that I never remotely expect. They have threatened to break up with me so many times that we’ve agreed that I just shouldn’t take them seriously when they bring it up. They’ve also told me many times that they would probably kill themself if we broke up.

Once they said that they might kill themself and that it’s over between us and they ran out of the house and drove away. It totally broke me at that moment I really thought this time they were going to die. I lost my sister to suicide and I didn’t want it to happen again. I called emergency services and tried everything I could to find them. When they came back they told me that I deserved to think that they were going to die because I made them feel that way. They were also mad that I contacted people.

Our relationship didn’t start out like that. My boundaries have been gradually pushed to the point were it feels like anything could happen. The first time they screamed at me like that I left the house, then they went after me to apologize and beg me to stay and said it wouldn’t happen again. And eventually that kind of yelling was normal. Every time that I genuinely think that they are going to die or genuinely think that they are going to break up I care just a little bit less. I don’t want to feel that way but I think it’s impossible not to. That’s what tears me apart.

Things haven’t been as bad lately with us because things are just going well for us right now. There’s still passive aggressive comments and occasional put downs but for every one of those there are at least 10 sweet things things they say that just melt my heart. But I’m afraid that when things get bad again it’ll be worse than before.

When I try to bring up these problems it just sends them spiraling and it escalates to yelling and threats. I have tried to bring it up so many times but it is always met with anger. I want advise on better ways to nicely have hard conversations. Last time I seriously sat down to have a hard conversation with them about my needs they said that they couldn’t handle a conversation like that at the time. So we planned a date to talk about it. When that date came up we had to cut the conversation short because it made them have a kind of emotional break down and it really felt like it was all my fault.

My partner and I both want to have a family in our future, but I don’t know if I want that anymore. I grew up in a house with lots of yelling and it really bothers me on a core level.

I don’t even know how we could break up anymore. Our lives are so tangled and I can’t financially handle moving right now. I feel so alone because that can’t talk about this with anyone and it is burning a hole through my heart. Thank you to anyone who reads this and double thank you to anyone who replies. Has anyone here been in a similar situation?