P.M.
I had a similar situation with my mom, who lives right next door, so I have really had to deal with it. Surely the hardest emotional work I have ever done, and because neither of us plans to move away, the work goes on.
The most important thing I realized is that the concept of "mother" is blown out of proportion in our minds. If you explore the pain you feel, I think you'll discover that it's mostly because some part of you has been trained to believe your mother is somehow more right or more powerful than you. That was true when you were a helpless baby and a dependent child, but you are an adult now, and have as much (or more) likelihood of being a good parent as she had. There may also be some part of you that is terrified that your own children could end up feeling about you the way you feel about your mother – almost like you will curse yourself if you don't treat her with the appropriate love and respect.
I'm not sure exactly when I made this discovery, maybe in several smaller steps, but I finally "got it" that my mother is a flawed human being, and is no more right or powerful than anyone else, including me.
Wow. I almost laugh/cry everytime I realize that. All those years of struggling for her forgiveness, cooperation, love, respect… . No. She's my mother by accident of birth. Not my fault. Not her fault either, because she had four "accidental" daughters and has let us know she would not have chosen to mother any of us, had better birth control been available way back then. Of course she "loves" us all, but that seems to be as much something she believes she has to do as a simple truth that she experiences. The latent resentment and anger toward how her children changed her life still emerges today, and the resulting dynamic is that she believes we owe her love and respect because of all the sacrifices and hard work she endured on our behalf. And it's true, she did.
I have realized, though, that I do NOT want my daughter to love me for any grudging sacrifices I made for her. If she loves and respects me (and she does), it is because I love and respect her, admire her strengths, feel compassion for her weaknesses (some of which I surely contributed to when she was little), believe utterly in her unique wisdom, freedom and worth, and am grateful that she is in my life.
My mother gets my genuine love and respect to the degree she sees me, and treats me with love and respect, not because she holds the position of "mother" in my life. We are getting there, and if she's around another 10-15 years, we may make it. Until then, she has my compassion and as much patience as I can muster. Sometimes that's a lot, sometimes she "expects" in a passive-aggressive way, and I simply choose not to see her much.
And you know what? That's not only okay, it's pure, loving sanity. I don't give her anything of real value if my "love" is forced, if my "respect" is an act. From what I have learned about guilt and codependency, neither of those adds a bit of true happiness to the world, even though my mom might find them gratifying. Gratification and happiness are not always the same thing.
I think Carrie is right – forgiveness is for yourself. You can do this work independently of talking to your mother, though you might want to tell her some day when you manage it. And here's what I know about forgiveness: it means you have simply given up all hope for a better past, whether that's your childhood or the fight last year or the discomfort you felt one minute ago. It was what it was. Period.
At every moment, you have another chance to let it go and start from here. We can't change any of it, can we, except for our wish that it was somehow different?
So what if your mom wants you to apologize? That's her issue. If you have anything to apologize for, you get to decide what that is and when you're ready. If you have nothing to apologize for, you don't have to. You could write her back and simply say you can't find anything right now to apologize for, and have been feeling calmer since you've been out of touch. Period. No reasons, no excuses, no rationalization – just sweet and simple truth. (By the way, this is one reason I strongly believe we shouldn't make our kids apologize until they can do it sincerely. Look at what those demands do to us years later!)
Will your mother like your honesty? No way. People hate it when their predictable relationships become unpredictable, when they lose the power they thought they had. Are you afraid of hurting her? Sure, but you won't be hurting her, the truth will be hurting her. If you don't live your truth, that will be hurting you, right? Live from your truth. You've already found out how good that feels.
Hmmmm… I didn't realize how much I had to say about this. Blessings.