Well that's never a fun position to be in.
I want to applaud you so much for coming here and talking it out before doing anything physically. It can be very hard to overcome an addiction, and you're making a really strong move by even pushing it aside even if it's just for a moment. I'm not sure for how long you used to self harm for, but even if you haven't done it for a few hours, days, or months, then that's a HUGE accomplishment!
It's ok to want to harm, and it's ok to even say that you are thinking about it. Just speaking what's on your mind, your feelings and emotions and desires and wants, that can be very powerful and helpful. I personally find a lot of help in writing and talking about things like that. It doesn't make you weak to have the urge, it makes you strong to be able to stop and think and say "wait, let me talk about this first."
As weak as you may feel, that alone makes you stronger than many.
It's a journey, a route, a road, a struggle - As with overcoming any obstacle in your life, it takes work. There may be setbacks and bumps along the way, but that doesn't mean that you've failed or broken! Just because you may make a mistake or falter in the future, you're still working and changing, and it's a process. Don't be afraid of the times when you may resort to cutting, but be proud of the times that you can overcome it (even if it's not every time!). No one wakes up and is suddenly where they want to be, but the fact that you can even be open and talk about this, that shows a growth of leaps and bounds.
Finding something that works for you, other than self harming, is a great way to divert how you deal with the stress. Simply NOT cutting doesn't deal with your emotions and doesn't deal with your stress, so you still need to find another outlet (think of a pot with boiling water - just putting the lid on doesn't stop it from overflowing!).
Have you tried seeking professional assistance about this? Talking to a doctor, councilor; even parent, teacher, trusted adult, or friend. Getting our feelings and emotions out in the open can be very helpful and therapeutic.
We all have rough patches in our life, and while I don't know what's going on in yours I do know that you are not the first nor last person to get very upset with your struggles in life. While your situation may be unique or "different", there are people out there who would like to listen or help (as I'm doing right now). Life has a way of piling on a lot of mistakes all at once, so that it feels like more than we can handle. I understand that it can be hard to not dwell on the negatives and mistakes, but it is important to at least try to see past them and to try to find positives in our world. Even if it's something small (like a pretty flower on our walk home) or something large (like a great romantic partner who loves us dearly).
Next, what are you doing to handle this situation? Sitting at home in the dark and crying can sometimes be relaxing, but in the long run it's not going to help anything. As I mentioned above, getting your thoughts and emotions out can be very helpful: writing, creating a blog, even posting on LiveWire can all be ways to get our mind out there to the world. A lot of it can even be anonymous, so if you're worried about judgment then blogs and forums can be a wonderful way to get out our feelings without fear.
I've found a lot of comfort in writing letters. Even if I don't send it to the person who may be upsetting me or stressing me, it helps me a lot to get out all my emotions and hurt onto a piece of paper. Then I will delete it, burn it, rip it up (which in itself can feel very good).
Don't be afraid to tell someone how they can help you. No one can read your mind, and you deserve to get support how and when you need it. If you want your friends to just listen then you need to tell them, if you want your mother to help you find a doctor to speak to then you need to tell her, if you want anything else from anyone then you need to tell them. You need to take control of your own choices and do what you can or need to to make your life as wonderful as it deserves to be.
If there are certain times or stresses in your life where you need help or to talk, feel free to come back on to LiveWire, or you can even write a blog, or write on a piece of paper (like I mentioned earlier, it can be very therapeutic for me to write down what's bothering me on a piece of paper and then to rip it up into tiny pieces. It's like I'm getting rid of it, plus it's nice and comforting to "destroy" something.).