Thank you Tilly. I've been with my partner for about 4 years and he was diagnosed with PTSD around Feb...
I can really relate to this, sillymoo. I have some advice for you from my ups and downs with my partner, which is to make sure to take care of yourself and create boundaries with your partner. You did not cause his moods and issues, and you're not responsible for his behavior. When his behavior affects you, you're allowed to protect yourself. Otherwise, you will exhaust yourself and will not be able to care for him as well :)
One thing that really helps with communication is active listening. This starts with mirroring what your partner is saying when they are frustrated to be sure they are heard and understood.
So for example:
Him: You're making me so angry.
You: I'm making you angry?
Him: Yes, what you did made me angry.
You: It sounds like what I did made you angry, is that right? I really didn't mean to upset you when I did that, but it looks like I did. I think we should take a break for the rest of the night in separate rooms to calm down.
It's really hard to practice this, since our first defense is naturally to formulate our response before the other person finishes speaking. This helps to improve misunderstandings.
Another thing you will see a lot on this forum is to make sure you're setting clear boundaries. A clear boundary might be that when your partner starts to fly off the handle, you might say, "I understand you're upset, but abusive language is unacceptable. I'm going to leave and check in tomorrow, because I can't talk to you when you're acting this way."
It's hard to strike that compromise between being loving to a healing/hurt PTSD partner and standing your ground clearly, lovingly, and honestly to preserve your own sense of self.