I have looked at bad pictures before. Well, I don't know if the pictures themselves were bad, but I looked at them in a bad way, or both looking at bad pictures and looking at pictures in a bad way. I have also thought or imagined bad things before, and I know doing these things is wrong. You told someone before that the Bible does not say that you have to tell people you sinned unless it harmed them in any way. Well, one time something happened (involving a bad picture... I think you know basically what I mean), and my mom was talking to me. I think she said that she knew I wouldn't look at stuff like that. Around the time she said that, I don't think I had been looking at bad pictures, or looking at pictures in a bad way (or both) (I think you know what I mean). But before, around the time she said that, I think I might have been looking at bad pictures, or looking at pictures in a bad way (or both). I didn't tell her that I used to look at bad pictures, or look at pictures in a bad way (or both). I don't think not telling her would have been harming her. What do you think? Also, until recently, I had been looking at bad pictures, or looking at pictures in a bad way (or both) for a while I think. I said "until recently" because I am hoping to have stopped.
The problem is that you know you've been sinning, but you don't want to admit it, even to yourself let alone to your mother. That is why you are avoiding talking about the problem plainly. You've been looking a racy pictures of women and possibly also pornography. You've been imagining having sex with these women and masturbating to those mental images. Your mom caught you once, but at the time she caught you, you were trying to quit. You didn't say anything and left you mom with the impression that someone else had the picture and not you. Since then you went back to looking at pornography or near pornography again. But in the last few days you're trying to stop again. Because it has been a few days, you think you've conquered the problem, but you are not sure because you have had relapses before.
Is that a more accurate description of what is going on?
No, you should not have lied or let your mother believe a lie. I know the whole topic is embarrassing and you already know it is wrong, but it is easier to conquer a problem when it is out in the open. Whether you need to go back and correct this with your mom, I'll leave up to you, but right now I'm more concerned that you deal with the issue that you are getting addicted to pornography. "For this is the will of God, your sanctification: that you should abstain from sexual immorality; that each of you should know how to possess his own vessel in sanctification and honor, not in passion of lust, like the Gentiles who do not know God" (I Thessalonians 4:3-5). "Passion of lust" refers to getting sexually excited over things designed to make you sexually aroused -- in other words, pornography. See Why is pornography tempting?
There are two halves to the problem of pornography. One side is that it feels good to be sexually aroused and even better to ejaculate. The other side is that the male body does need to ejaculate periodically. The desire to ejaculate becomes demanding if it is ignored. Pornography interjects itself between those two halves. It makes ejaculating easier and leaves you with the impression that the only way to relieve the need to ejaculate is to masturbate to pornography.
What you have to do is learn self-control. Admittedly, it is a battle, but it can be done. The method is actually straight forward. First, you have to admit that you do need to ejaculate. If you try not to, you will eventually fail and start telling yourself that you can never be good. So, you give yourself permission to ejaculate, but it will be restricted to a place where you can't get to pornography at the time -- in the shower. You wait until you notice the desire for sex or even the temptation to look at pornography gets strong. Then you go take a shower and relieve yourself while you are in there. You'll find that afterwards the desire to look at pornography disappears, you might even think that the whole thing is disgusting. Eventually it will fade and the desire will build again. Your goal is to stretch out the periods between ejaculating. Not so long that instinct takes over and you given in to looking and not so short that the only way you can get yourself to ejaculate is to imagine yourself committing fornication. It will take a while, but eventually you'll find the happy medium between the two where you can keep control of your thoughts.