I need advice please help me

I am 19 years old and I have been with my boyfriend for three year. I live in north California and he lives in south California he is the only man I have ever been with and I love him so much. It hurt when we aren't tigether and we talk and text all day and give each other goodnight a every night. He has changed him self for me because of how much I worry. But when he asks me to do things for him such as call him when he is upset even when I know I should I don't. I don't understand why I do this and it's hurting our relationship I don't want to lose him we have been though a lot together. I can't remember things he has asked me to do and when I get upset when we argue he has to repeat himself multiple times even though I am listening I can't remember what he said not even a minute ago. Today he told me he was sick and I didn't even ask him what was wrong and when he asked me to call for just five minutes I for some reason didn't call and spent the whole day doing a essay. He got really up set and I just seemed to give him any answer when he asked me why I did it because I didn't know why myself. He gets annoyed when I tell him I don't know why I do things all the time. Which I understand I would be too if he did that to me. If any one has advise I need it this is my first boyfriend I haven't had to face this problem of mine before and I need to now