Question about mental health

Hi all, I hope everyone is doing well. I've been thinking about how MS affected my personality, my mood and my mental health in general. So, I'd love it if you share your experience with me. My symptoms started in April 2018 and the official diagnosis was in July 2019. I started treatment in October 2019. Since 2018 until I started treatment I feel my personality was different in that I was emotional and careless about my life and my studies. I'm a PhD students. I remember in 2018 I wanted to quit which is unlike me. I almost did but my family and my supervisor encouraged me to continue. My question is has anyone felt like they were different mentally before they started treatment?