Should i tell a friend that I've decided not to be friends again?

To make a long story short, I was friends with this person for about 10+ years. She was a close friend but never a friend who i told my inner most secrets to. She moved away for 5 years and moved back. Thought we could start off where we left off, but i was a different person and she came back with a lot of drama & in a dark place. We argued a lot because she saw me as "perfect" and that i didn't have problems. We got along at times but only when she was having a good day. Otherwise, she constantly threw up on me with her problems (which were the same for about 2 years). She seemed to thrive on drama. I tried to help her, but she never wanted my help. It eventually got to the point where she decided to take a 'break' in our friendship. A long letter was written where i was blamed for stuff i never said or things were assumed about me or things i said were taken out of context. She let herself believe that i was certain way and made others believe it to. Bottom line, i felt betrayed. Fast forward to June, i decided i missed her and that i wanted to try to work things out. I chickened out of the meeting & have since decided that i am better off without her. I am stress free and living life drama free. I feel better as a person and am happier. So, do i owe her an explanation as to why i decided not to contact her again? or do i just let it be?

PS. We haven't seen each other or really talked to each other in about 4 months.