My mom appears to be excessively emotionally dependent.

Hello, as the title suggests, my mom (50F) has always been really dependent on both me (19F) and my dad. I recently moved away for college, and I can only visit home about twice a year because it's far and expensive. Honestly, I’ve never felt happier—I was so unhappy back home, and moving has been the best thing that’s ever happened to me. However, my mom has been asking me for a good morning and good night call every day, wanting to know what I’m doing, who I’m with, and more. While I can manage this to some extent, it’s been months, and it’s getting overwhelming. With my busy school schedule, I barely have time to sleep at night; I can’t be on the phone for three hours a day. My dad visited me this week since my mom couldn’t come due to visa issues. Now that he’s away too, she’s calling me even more frequently, which I understand, but a few days ago, I missed her call because I was occupied. I hung up and texted, "I’ll call you back," but when I called back an hour later, she was in tears, yelling at me for hanging up. She said I was her whole world and accused me of not caring and disrespecting her upbringing, saying she regretted sending me abroad for college. I tried to explain, but she wouldn’t listen. I eventually handed the phone to my dad to handle it because I was really upset. Yesterday and today, I called her three times, but she’s been cold and distant. Her eyes were puffy, and she mentioned feeling physically and mentally unwell but said she couldn’t talk to me about it because I never liked what she had to say. She’s been in bed wearing the same clothes, and I suspect she hasn’t eaten for two days. I’m genuinely worried, but I’m also incredibly frustrated because I don’t understand how to handle this. I feel guilty even though I don’t believe I did anything wrong. This situation is draining for both me and my dad, and I know it won’t be the last time this happens. The same issue arose when my dad and I were both away before, and now that I’m away for good and he has several upcoming business trips, I’m at a loss for what to do. What on earth should I do? 😭 TL;DR: My mom calls me four times a day, and when I declined a call once due to being busy, she got angry and has been in bed and not eating for two days. This isn’t the first time something like this has happened.