How can I improve my relationship?

First priority would be to find your own balance and prioritize reducing what is causing you conflict. That can be a time consuming process so in the meantime it is important to try to increase healthy communication with your partner so that they do not mistake your frustration as irritation with them. When we're in the heat of a moment, it's often not the best time to say something to your partner. When we are emotional we are not always thinking rationally. Changing your timing can have a profound effect on an interaction. And, when you change your timing, your tone naturally changes. Let's say you and your partner have tension around dinnertime. You get through that and get the dishes done and clean up the kitchen. You've been thinking about your part in things but you're still upset, although it's better. Now there's some free time around 8:30pm and you go to your partner to finish your earlier conversation. Because you've waited and changed the timing, your tone is immediately better. You're less upset so the issue is less "hot" and the words you're using with your partner are more gentle and thoughtful. The conversation will now go completely differently.

Timing and tone is huge. You can say pretty much anything you want to say, just not when you want to say it. Waiting for a "better" time is almost always the way to go. I say "almost always" because: Be sure you are waiting for a "better" time not a "perfect" time. There is no perfect time. Don't let things go for days or weeks. The timing can be delayed (while you're making sure you're going to have a response and not a reaction), but you generally don't want to wait more than 48 hours. Sometimes people wait to have the conversation but then never have it. That doesn't work. What often happens is someone will wait so they'll have a healthy response, but then they feel better and tell themselves it wasn't such a big deal. They're thinking, "We're getting along great now - I don't want to ruin it!" It's healthy to delay certain conversations, but it's not healthy to eliminate them. Whatever the "thing" is will continue to happen and you'll build resentment.

Even though I said all that, maybe you really can let it go. Sometimes you wait and then realize that whatever you fought about really didn't bother you and you really were overreacting so it is okay to just let it go and learn from the situation. In the end, when you focus on having a delayed response and not a delayed reaction, it puts you in a healthier, more open mindset - this is the best place to start any conversation. Remember to check in with yourself and to come from love, not fear.