Know that you are not alone in this! I don't know why some parents are this way and some aren't. My mother was very clingy, all throughout my 20s, and I still struggle to fend her off in some ways.

There is no way to please them and yourself. They will be angry when you start to cut the strings (like you are doing) and there's no way for you to cut the strings that won't make them angry. At the same time, you have your life to live. They need to make their own friends and develop their own life that doesn't revolve around you, just like you need to make your own life that doesn't revolve around them.

I found it interesting to find out how people my own age related to their parents, how often they talk. Talking to your parents every day is a lot. You deserve your independence.

All the crap they are giving you about renting a car or not renting a car -- that is manipulative. Wanting to be independent is natural. Taking a vacation instead of seeing your parents - that is normal. You do not owe your mother anything for driving to pick you up.

I found that if I threaten to withdraw even more, my mother behaves a bit better. Tell your mother that you will have to get off the phone if she keeps harassing you about your vacation, then do it. After a few times, she may wise up and at least feign happiness for you