Need Help with Hurt and Pain?

I am shocked beyond anything, today. I always answer but today I need all of you. I am named LaDonna and my best friend of 20 years WAS named Donna. All though the years it was one sided. I always heard her problems and dealt with her problems. I watched her kids, fed them and she knew she wasn't supportive of me. She said so one time. But I am guilty of helping people all of the time. I could go on and on but it's simple. I began to open up to her about me. On 7-25 I received the cruelest e-mail I have ever seen or read. She shredded me, tore at my kids and my husband. Even my house. But my kids? They are so precious to me! She's so cold. I examined the last 20 years and let it rip to her. I know two wrongs don't make a right but just yesterday I was praying and somehow in my soul I knew some of my friends have just been users. She's a cruel, cruel woman. I know we are divided in this forum but alot of us have kids. The last thing I'd ever do is rip and tear at your kids out there. Maybe I have solved my own problem. I got the e-mail. I realized it had been one-sided for 20 years. Twenty. A very long time. When I read those cold words about my kids, I let it rip at all I've had to hear for twenty years. Here is an example. She left her own two girls to trot off to the coast and live her own way. She left her kids with a man who loves them but still uses them against their mother. These girls began to doubt their mother. She then was having two affairs going. She got pregnant. She lost it. In all of this, she got pregnant again. She lost it. This so-called friend was in the bathroom. She held the dead fetus and then flushed it. I am deeply hurt. I whited out her name in my address book. Should I let it go? Am I done with this twenty years? Have I done enough? Where did I go wrong? Please don't tell me I am stupid or am a sucker. I already know that. Just looking to resolve it and bury it. Thanks, everybody and you know? I love your kids! P.S. I think she's afraid to continue being friends. She is married to a man (one of the guys from those two affairs after she divorced the other guy she married from the other affair). Her husband is bad news. But I think her desperation made her marry a man she made fun of! But, it's his house. No, her girls don't live there. She doesn't even have any pictures of those girls in HIS house. Also, she can't tell her husband the truth about herself. Her marriage is built on a house of cards. Should I continue to care or walk away and let her just unravel?