Help! Last minute change and i don't know what to do

Considering it is only a few days away, I think you need to still honor all the people that said they were coming. I would start ASAP contacting them all that the location has changed.

I'm sorry you had a falling out with your dad and siblings so close to the wedding. Any particular reason why the resent you for planning to have the wedding at your dad's house?

If you are moving forward with your back-up plan, you need to notify everyone immediately. It would be extremely rude of you to only include your immediate family after sending out formal invitations to your other guests. Your wedding is most-likely something they've cleared their schedule for, so they should still be informed and invited to your backup location.

So sorry this is happening just a few days out from your wedding. The first thing you want to do is immediately contact all of your vendors and switch the venue to FH's Aunt's house. Then you want to immediately contact all of your guests and tell them something like "Due to some unforeseen circumstances, the dynamic of the wedding has changed, and will no longer be happening. We apologize for any inconveniences, and please know that this is beyond our control. With our deepest apology, we thank you for understanding." Something like that. Do you have guests that were traveling from out of town that had to pay for plane tickets or anything like that? If so, those guests should still be included. If it complicates things too much to still include some and not others, then simply sending out a change of venue notification to your guests and keeping the list the same could be an option. I don't know, this truly is a messed up situation for you, I am so sorry.

I had stopped talking to my dad as a teenager. There were a lot of issues between him, myself and his now ex wife (my sisters mother). I was finally ready to come back into contact with him 5 years ago and we've been okay. I found out that they all thought I only came into contact with him because I wanted to him to pay for my wedding, untrue. I came into contact with him 3 years before I even met my FH so that doesn't even make sense.... I just can't in good conscience let him pay for anything else and have them thinking that of me. I can't have a wedding full of that tension and resentment

When you say they, you mean your dad thinks this as well? Why would he allow you to plan a wedding at his home if he didn’t think that highly of you?

If this is just your siblings, then I would proceed with the day as planned. If they don’t care for you, then they don’t need to partake in the celebration with you on your day. At the end of the day, this day is not about them, it is about you and your FH love for one another. You can deal with drama later. This is supposed to be the happiest time for you.