In arguments he says horrid things...

[noideawhati]

We're engaged, no kids, 1 dog.
We've had our ups and downs but whenever we fight, he always says things along the line of "can't wait to get out of here" "god I don't want to be with you" "I just want to break up"...along those lines, sometimes a lot meaner/ more swearing.

However we resolve fights very quickly so within a few hours he will be back to acting okay with me and I never bring up what he's said as I always put it down to anger.

But I realise it's not right and feel very lost and heartbroken.

This will be your life. Is that a happy thought?

I don't think this is a good sign at all. What's the rest of the relationship like?

Does he apologise and retract any/all/some of his comments?

My exh used to threaten to leave. Every argument.
Best day was when I told him to leave.
Mh improved ten fold.

Don't marry this man, it will destroy you.

Echoing @vacanthellhome

Get Out. He's a nasty fucker who will bring you down.

It's not anger OP, its NPD

Really not good... does he do it every single argument? May I ask what are your arguing about? It is about stuff like someone not picking up towel off the bathroom floor, or more "serious" relationship issues? Is there an ongoing major underlying issue that is not being addressed and he is deep down angry about that, rather than the actual thing being argued about?

It isn't necessarily NPD but he's a shit.
You need to end it.

No. It's NPD. No normal person would say things like this.

The other obvious pointer is quick to forget about it. This is black and white thinking.

He’s a manipulator... do you want to marry a manipulator?

My Ex also used to threaten to leave. After so many times of putting up with it, I said please do. He was beside himself but I'd had enough. Maybe you should call his bluff Op.

Diagnosing someone with BPD based on a few lines is utterly ridiculous.

How often are you arguing OP, and what about?

*NPD

I used to get the threats to leave too from my ExDH. And yes, one day after 25 years of marriage I said 'good idea, off you fuck'

Life got a lot better after that. Do not stay with someone who makes threats all the time: It's manipulative and controlling, as others have said.

@NoBaggyPants @megrichardson has just said the magic word...manipulation

I would not marry this man, if I were you, OP. He is showing you, with blinding clarity, who he is. I don’t think he is going to change, and if you marry him it will be a lot harder to get out of the relationship.

You need to speak to him about what is/isn't acceptable during an argument.

He is training you not to argue with him. Take the dog and leave.

My ex did it. In arguments he'd say horrible things, call me names (cunt, whore, all sorts), tell me he wishes he'd never met me etc. Once he calmed down, he'd apologise but that cycle continued for 6 years. No more.
Don't put up with this, OP. Leave him.

I agree with every single person on here - get away from this man.

Agree with when you leave to take the ddog.
Do not subject an animal to his bullying.