Family planning problem.

So I have been engaged since last year planning on getting married 2021! Anyways planning this wedding has caused a huge rift between my grandma and I. For a long time I wasn’t allowing her to pay for the wedding or be involved in any planning because everything I wanted she wouldn’t pay for unless she liked it. Her idea and my idea for this wedding are completely different. Anyways over a lot of talking we agreed to let her help with the wedding as long as she doesn’t act like that and be hateful to me, and stops buying stuff without my approving it. She continuously tries to add people to my guest list. Then I find out yesterday from my mom that my grandma is buying stuff to decorate my wedding with that I haven’t even seen. It infuriates me to the point I want to cut her out of planning all together again. She also hates my wedding dress and has multiple comments like oh I don’t think it’s for a black tie wedding ( we are not having a black tie wedding). I hired a wedding planner to avoid this but now she is just doing stuff behind my back. I feel like I’m going to get a wedding I hate! I don’t want her to waist money and I know it makes her upset when I tell her I don’t like something she has spent money on. I just don’t understand I have made it very clear to her I want nothing purchased without my approval. What should I do!!!! My grandma is pretty much my mom she raised me for 12 years.