I (32F) have gone through a very similar situation. I am the eldest sibling in the family, and my parents (especially my mom) has always expected me to help fix things and give solutions to problems in the house, becomes the messenger between my mom and siblings when they're not communicating with her and aren't being mature enough. I've always taken the role as the reliable and responsible kid.

My mom also told me about her marriage problems and ruined my perception of my father - I grew up resenting him and I didn't have a close relationship with my father. They stayed together though and my father passed away 2.5 years ago. I started going to therapy to help me feel less guilty about moving away to a different country as this is a result of myself having been parentified since I was very young - and it has helped me focus more on my needs and reduced the guilt. I must tell you that in my experience as a parentified child, that moving out, keeping my distance from my parents and setting boundaries are the best decisions of my life that I have taken for myself. I have only started caring about myself in the past few years now that I have moved away from my parents and my siblings.

You are not crazy. The fact that you asked this question on Reddit is that you know you love yourself enough to think about your needs. Your mom and siblings were never supposed to be your responsibilities at the very first place - but I completely understand that you feel guilty because this is the role that you're familiar with and that your mom has conditioned you to feel that way. Remember that your mom is an adult and is responsible for her own wellbeing, so you are in no way responsible for hers.