Should i Allow My Mother to Attend My Wedding?

Note: This is very long, I do apologize.


Hello,

I’m getting married 9/25/21, so a month from today. My mother has struggled with drug dependency issues for the majority of my life. She had been clean for a while, but for the last year my brother and I have noticed certain behaviors with her and have questioned if she was using again. About a month ago I received confirmation of this from my mother’s boyfriend (whom she lives with). They are in a very volatile living situation and my mother is claiming he is making everything up. However as I said my brother and I have been down this road with her before and know what she is like when she is using. It was also very obvious to other people who hadn’t seen her in years at my bridal shower last month, that she was on something. I drove up to where she lives, with my brother and fiancé and tried to convince her to get help, I even found a rehab facility that takes her insurance and can provide living arrangements for after treatment, as she is getting kicked out of her boyfriend’s house. She is refusing treatment, denying the severity of the situation, and believes she is fine. She thinks everyone is against her and refuses to talk to a professional. I have tried every resource I can find to get her help, but I also feel defeated at this point as I know it has to come from her and I can’t force it.
When everything came to light last month, I seriously considered postponing the wedding. We are however paying for it ourselves and we would lose a lot of money doing so. People have also taken the time out of their lives to plan to be there, paying for hotel rooms, travel arrangements, etc.. I know we have to move forward with the wedding as planned, but I am heartbroken over the situation and feel torn.
After speaking with professionals in addiction, I did issue her the ultimatum that she couldn’t attend the wedding if she didn’t seek help. I know I can’t enable her and she needs to hit bottom to see it for herself, but this is obviously a very painful situation. I want her there more than anything, but I know in her current state she wouldn’t really be there as my mom. This has consumed so much of my brother and I’s lives (the last time this happened was when we were in high school and it started when we were kids). My heart breaks at the thought of her missing this day, but I don’t know what else to do. She doesn’t see what this has done to us, or her life as well, and as much as I want to I don’t have the power to fix it.
Am I making a mistake? I don’t want to look back at this time 10 years from now and regret the decision I made, but I don’t know what to do. I wish it was different, I know this is supposed to be a time of joy. I know my fiancé was heartbroken when I first brought up the idea of postponing. We have been waiting for this day for a long time.
I’m scared for her, I’m scared for our relationship, and even if I follow through on my ultimatum I don’t know if she would respect my wishes and decide to show up out of the blue anyways. Any advice would be very helpful, I’m truly out of my depth. Thank you!