I don't know what to do

I love my mom. I love her so much and I've been keeping this secret from her and the rest of the world for too long. I feel like I've done something unspeakably evil. I don't know what to do! I want to tell her and I know its the right thing to do, but I don't know how. She always says that I can tell her anything and I fell like I SHOULD tell her and I know she'll love me no matter what it is. But she always tells me how proud she is of me and my siblings and I feel like if I tell her she'll feel like it was her fault. But it wasn't, it was completely my fault and I feel like shit about it. I don't know. I'm just confused. I mean, I'm not a bad person, right? Ugh! I'm sick of secrets!

I know that I don't really know mostly anyone on mibba, but I feel like you're the people to ask for advice. I'm going to tell my mom tonight regardless, I just....I guess I just don't know how.