Difficulties in Communication

I got in a fight with my mother last night. As I expressed in my last post, I have been having a hard time adjusting and have been pretty down lately, and my mom managed to add stress and say the wrong thing to me and I just exploded. I told her that our conversation was over and I hung up. After I hung up, I sat there fuming. I was upset and mad and all worked up. I realized I would never sleep if I left it like that; I needed to make things better, at least better than that. I calmed myself for a minute, gathered my thoughts a bit, and called my mom back. I explained to her exactly what I found so stressful and frustrating about our most recent conversation, and our communication in general. I told her how I had been feeling down, and what I needed was positive feedback and encouragement right now - that I just couldn't deal with added pressures and critical remarks. That speaking to her often added stress to my life, which was why I hadn't been in touch so often lately. I told her that I knew that she loved me, and cared about me, and that I knew she didn't intentionally try to upset me, but that I couldn't handle some of it right now as I was dealing with too many other things. She thanked me for bringing these points up and for being honest with her. She acknowledged that I had valid points, and that some of them she couldn't do anything about, but at least she now understood how I felt. She told me that she did love me, and that she was sorry that her actions upset me, but at least now she knew. The second phone call was ended on a much more positive note than the first. Yes, we acknowledged that there are conflicts between the two of us, but at least we are trying to accept them and work with them. I was glad I had made that second phone call and cleared the air. It opened up a lot of pent up frustration and guilt I had been holding on to for a long time. It gave my mom a much better understanding of what I have been going through and what stresses I can and can not deal with at the moment. It also helped her understand why I sometimes get frustrated with her - which is a hard thing to hear but I really believe can help two people in improving their communication in the long run. I hate being caught up in a misunderstanding, and feeling that I have hurt someone, but not really being sure what it was that I did to cause that hurt. Even if it is hard to hear that I have done something to make someone else feel bad, I prefer knowing what it is that I did to hurt that person, and having the opportunity first to apologize and second to try to ensure that it doesn't happen again. I can't do that if I don't know what I did in the first place, and I can't expect someone else to either if I am not honest with them. It's not always easy doing this - being up front and honest about exactly what is bothering you. I think it takes some reflection to figure out exactly what it is that is the problem, and then it takes a lot of tact and the right tone to express those feelings, because if it is expressed harshly or accusingly, it can just make things worse. It's really hard, and it does sometimes backfire. But I think honesty ultimately makes a relationship stronger. What's hard is knowing when to continue trying and when to let it go. In the past, I have had relationships end because I could no longer figure out how to make things better, and I was left with a feeling of unfinished business and loose ends that made me very uncomfortable. I couldn't do that with my mom, she will always be in my life. How much effort should one put into resolving misunderstandings?