Family issues on wedding day

I cannot wait y’all!! The day is today!
I’m just feeling a bit let down by family members. During the whole planning, my family has been an issue (so has FH but for different reasons). First they offer to buy the cake as a wedding gift because they hated the idea of donuts at the wedding, so FH and I chose guava filling in a vanilla cake and are excited but come to find out that they can no longer pay the cake and we are left with 380 bill we didn’t account for. They also are complaining that we were selfish in choosing the flavour because it was a gift from them and they should be the ones picking it. Mind you they were brought home left overs from tasting.
My mom is constantly trying to get us to spend our wedding budget on her like to pay for makeup or dress and we kept telling her that if we had extra money we would but that the bills came first. She was so upset and said we were hiding money to not help her on purpose. In the end we had to go over budget and every time we did so, she kept asking for more and more things to be paid.
last night at my rehearsal dinner they asked if they could come and borrow my car for the day of and I said no problem but if they could come pick it up because I needed sleep to be rested for today. They caused such a scene because I wouldn’t drive 40 minutes (back and fro) after my rehearsal dinner with few drinks in me and called me a selfish daughter. Also said oh don’t worry if you don’t do this then we don’t have a way to get to tour wedding so you decide.
my FH saw me stressed and upset and didn’t let me cave into their demands so I didn’t drive over there.
Im unsure of what to do because I want my family there and my dad to walk me down the aisle but it’s been costing me my peace of mind. I do nothing but worry over them and how to help them. Am I overreacting or are they really being unfair and toxic?? How did you deal with family issues? Looking for advice y’all