I want to do good

Novice and I have been together for a bit over 5 months now. It's this phase where my relationships often go to hell, and I'm worried. I'm worried that my worry in itself will make me more on edge, more stressed, and thus it becomes a self-fulfilling prophecy. 

I worry because we keep having... I want to say fights, but we aren't fighting. Not at all. We're hurting. Hurting ourselves and each other, through misunderstandings, misconceptions, wrong assumptions and general miscommunication. And we're both too mentally fragile, most of the time, to be able to prevent it. So it keeps happening. 

It's just happened again, in fact. That's why I needed to write. 

They're angry at me, and hurt, and upset, and I can't fix it. I want to, but I can't. It's too late. I messed up, I said stuff I shouldn't have, I had the wrong tone of voice, or the wrong timing, a wrong turn of phrase, or probably all of those at once (and probably other stuff too), and I broke something. Again. Something unfixable. 

That feels... devastating. That there's no way to sort this situation out, no matter how much I want to try. And since I don't really understand what's happening until it's too late, I can't prevent it either. So I keep breaking stuff. Keep hurting them. 

Each time, I feel like I'm learning something. Growing, despite the pain and hurt. I feel WE are growing, too. Growing as a couple. We're not repeating the same stuff again and again, mostly. We solve most misunderstandings (eventually), and then (typically) don't walk into the same trap again. So there's progress. But I worry that I'm not growing quickly enough. because I keep hurting them! 

I can't keep hurting them like this, breaking them like this! I love them so much, the last thing in the world I want to do is hurt them! I want to do good. I want to BE good. But it doesn't feel like I am. It feels like I'm doing more harm than good right now. 

I want to be better. 

I just don't know how.