AITA for scheduling my wedding 6 days after my sister’s 30th birthday?

I (26F) am getting married to my fiancée (27F) next year. We found a venue we love and an available summer date (at the same price as a non-summer date, which is big in the wedding industry). We’ve considered a lot of factors for this date (niece and nephews school schedule, our work schedules, when my temporary contract ends, friends school schedules, weather, budgeting, travel, etc.) The date happens to be 6 days after my sister’s (28F) 30th birthday. When I told her the date she immediately thought I was joking because there was no way I could possibly have suggested a date that close to her birthday.

I explained to her how we are not having a bridal party and there won’t be events leading up to the wedding so she has ample opportunity to celebrate how she wants. She has nothing planned for it yet but says doesn’t want to have to plan “around someone else’s event”. She also said that it’s inconsiderate of us to have the wedding where we live because our older/sick family members will have to travel (I’ve spoken to them and they are happy about location). She also asked why we don’t just get married in 2028? or elope? and suggests that a 1.5 year engagement is really rushed.

After this I decided a phone call would be better to communicate bc this was all on text leading up. She said that she didn’t even think she would make it to 30 so how inconsiderate of me to not want her to celebrate it. She made many other uncalled for remarks like “I only get one 30th birthday but you can get married as many times as you want!”. And “since you won’t understand my point I’m not going to even try and understand where you’re coming from”. We basically got in a screaming match because I told her she kept guilt tripping me and making everything about herself. Not to mention this was the third conversation I had brought up about the wedding where she had reacted with judgement and self centeredness.

We didn’t talk for four days because everyone told me to give her time to cool off. I came back wanting to resolve things but she was not letting up. Her main points are that 1. Im not being flexible, 2. She now has no autonomy in planning her birthday, 3. I misled her into thinking she had a say in the date. My main points are that 1. She has so many options to plan a birthday celebration considering it is over a year out, 2. There are so many other factors at play in scheduling a wedding outside of her.

She has been so mean and disrespectful to me in these conversations that I have sobbed for the last few days and am practically begging her to recognize how the things she’s said to me have truly hurt me. She refuses to apologize.

I don’t know what to do at this point. I have apologized to her for getting heated, but not for the date because I genuinely think she can still have an amazing birthday celebration. Am I the asshole ?