Do you have some medical or physical disability that requires this specific seat? if so did you mention it.
No offence but if you arrive late, even if not by your own fault you should just humbly take any seat on offer and apologise for climbing over people. A lot of people like to sit on the edge. A lot of people would be mildly grumpy at people arriving late for mass as it may mean they miss something. I think it’s possibly a little unforgiving and a slight over reaction to consider going to another church for that. Haven’t you ever been a little grumpy or rude to someone in your life, ever? It’s likely they felt bad afterwards or not, that’s not your issue, you are called to love everyone even those who wrong you. It is annoying when people want you to move from a seat you got there early to get too, I can see that, personally I’d rather someone climb over me than scooch along. I have a disability and need the end but it’s not visible so no one is likely to know that. Still I am sorry you felt rejected, I hope you take a deep breath, relax and forgive them and be gentle and tender with people next time. Either go earlier or if you arrive later, then just climb past them with a smile and an apology if it appears that’s what they prefer. God bless you