How to cope with a clingy parent?

My mom is so clingy and it’s so annoying. People always preach to me about how lucky that I am to have a mom but they just live vicariously through me because they are very independent and have 0 relationships with theirs. Everybody gets to be happy and free but I have to suffer. My moms mom died a year ago and she always depends on me. Whenever I try to go places alone she always belittles me and treats me like a 4 year old when I’m 25. She has a son who gets to do whatever he wants just by the luxury of my old car that his daddy gave him. My mom always depends on me to go places all the time and my biggest thing is that she’s an embarrassment. She’s always yelling at me. She just makes me look like a 12 year old when I have my own car and pay my own bills. It’s irritating how she treats her son like a man when she whips has behind paying all his pills but gets more freedom than me. I guess because he’s a guy so he’s looked at as more “stronger” ha if he was so strong he would pay his own bills. He couldn’t survive in this world without them. I work from home but my mom never respects my job ever and always gets mad when my days don’t revolve around her. please help?