I did a very bad thing

That made bite my nails!
I lied to mom

I don't like doing that. I gave her money that my boyfriend was supposed to give her, but he didn't, well because he bought me a very expensive gift and didn't have enough money to pay my mom, when he borrowed some money from her to buy something... lol. I don't know why I'm telling this... Anyway, I paid the money for him, but he does not know that I did, and of course she doesn't know that that was my money, but surprisengly, she told me that she knew exactly how much I had, and I'm afraid that she would check my wallet or anything and would find out about it
She does not trust me, I know...