But with me having backups, and them being upset about it, saying i never said that (no you didn't hear it) and that makes me think they would be happier if I was alone up there?
Please give me some guidance and let me know if what I did was wrong or if this is an over reaction
First off, congrats on the upcoming wedding!
Second, your wedding day should 100% be about the bride. It's your dream day, it's every young woman's dream day. It's meant to feel special and because of that, pre-wedding jitters are completely normal. You have 100 things that could go wrong and you're probably thinking about all of them. Again, 100% normal bride-to-be behavior.
Third, look at the bold statement I quoted from you. Would THEY be happier? Where did I mention anyone but you in the first two points? Truthfully, weddings are about family and a lot of your time will be absorbed greeting guests, posing for pictures, telling the same stories many times...and everyone wants to hear it from you as they congratulate you.
What you don't want to do is worry about how someone else feels with a track record of causing chaos at family events. All the 'who said what' stuff, all the drama, none of that is about you and your wedding. It's about your sister and mental illness instead.
Whether you're right or wrong is not the question to ask here. It doesn't matter at all because this one day is all about you (and family, and pictures, and traditions...but stick with me, it's still all about you). You absolutely must let this go and allow your sister to say whatever she's going to say. If she causes problems, so be it; that's outside your control.
And if you can't control it, then don't worry about it. What happens will happen...no worry required.
Your only job is to be a beautiful, happy bride. Focus on your job and let the rest fall into place. I hope that helps!