Mental Health and School

So today I ditched 2 class periods because of how I was feeling. Recently I have been feeling sad and just sorta depressed. I told my mom she would be getting an absent call and she logged onto my status thing and asked why I was marked absent from 2 periods. I made up an excuse and she said she’s gonna call the school and get it fixed because obviously she doesn’t want me to mess up in school. I feel guilty having her deal with this but I’m not sure I’m ready to tell her how I feel. In the past, we’ve talked about me because I had a mental breakdown telling her how I didn’t wanna be *here* anymore and I pretty much broke her heart which is why I’m scared to tell her again. I don’t want her thinking I wanna kill myself, it’s just I’m sad and I don’t feel like she’d believe me if I tell her I’m depressed. I don’t have a reason either, I know many people have reasons and when you don’t have a reason for feeling some way, people say you’re doing this for attention and I just don’t want that reaction. I want to tell her the way I’m feeling so she understands why I had ditched. It’s happened in the past too, one day at school last semester I ditched the whole day except for 2 classes because of the way I felt. I just cannot deal with people and be around people when I’m like that. Anyway, should I be honest with her about the way I’m feeling and admit I was lying or should I continue with the lie? If I be honest, what are some ways I could tell her I’m feeling depressed but not wanting to disappear.