My long distance friend cancels last minute all the time

Me (25M) have a good friend (25F), we have been friends since boarding School so about 7 years Give or take. We live about 1 hour 30 min apart. I need advice, I have always set my time aside and said yes to whatever date she said she was available and pretty much everytime we meet its because i do the drive. She cancels always when we set a time and its always the day before or on the day. This weekend we agrees she would drive to me and we planned this after we failed to meet last weekend. now today i ask her when she was coming and she said “I thought it was next weekend” now to be completly honest im getting tired of having my mood ruined every time she cancels and I feel like I do everything, what can I do to salvage this or should i just start respecting my own time and stop the friendship.

Help.