feeling melancholy

I don't even know if I spelled the title right, but oh well.

It has officially been a year since mom and dad split and I cannot believe how my life has changed and how my relationships have changed.
A good thing is my dad and I are closer. I just felt so bad when she walked away. He has no family close by and I hurt for him. She will say I took his side without knowing all the details and she may be right. But I don't care. I do know, he was a good man to her. She was not abused etc... She went off her mental medicine and down the tube.
I don't talk to her at all, and that is good news too. When she is involved in my life especially now, she just causes havoc. I get stressed and then my family suffers. My hubby and little boys come first, a notion she has never accepted.
My sis and I's relationship changed some too, because she still speaks to mom and misses her etc... so there are lots of things I can't say to her and vice versa.
Divorce hurts and I am bitter.