Remove any objects you have used before to self harm from your immediate area. If you have to spend time searching for something to harm yourself with, you may just be able to crush the impulse. One minute can determine whether or not you self harm. Don't keep sharp objects on your table, and don't put razors in a close drawer or cupboard.
If you do not yet feel able to throw out your tools, try to delay getting to them by keeping them wrapped up tightly and high up on hard-to-reach shelves, and distract yourself when you get the urge.
If possible, give them to someone else. This is a guaranteed way that they won't be find-able. You'll be angry initially, but when it passes, you'll be thankful.
Keep rewarding yourself. For every day you went without harming yourself, draw something on a paper and put it on your wall next to your bed. So every time before you go to sleep, you are reminded of how strong you are. If you cut, you have to start all over again by taking down all the papers and starting over. Keep each bit of paper to remind you of your amazing progress in the future.
A similar idea is to make a paper chain. For every day you go without cutting, add a link. If you do succumb to the urge, you have to start over. The chain will be a concrete reminder of how well you're doing, giving you motivation to keep at it.
Try talking to a professional crisis clinician. It is clear that it is not their job to "talk you out of" harming yourself - you make your own choices and you must take responsibility for your actions. However, talking to your GP or another professional and notifying them of your situation will help. They may be able to tell you if you have the symptoms of a disease or disorder (depression, etc.) that may be contributing/causing you to self-harm. They may also be able to refer you to a clinic or support group.
You have nothing to be ashamed about. Self-harm is not an uncommon thing -- there wouldn't entire hotlines dedicated to it if it weren't! The professionals you're talking to have seen dozens of people like yourself going through similar situations -- heck, maybe they have, too. You are not psychotic, you are not worthless, and you are not an embarrassment. This is part of life.
Identify the triggers that make you feel like cutting. The moment you have the urge to harm yourself, stop and think of what has just occurred. Remember it and try to avoid these situations. Sometimes, they can be predicted and if they can be predicted, they can be avoided.
Some people are more likely to cut at certain times of the day. If you know that you're more prone to cutting in the morning, say, take extra caution just after you roll out of bed. Know yourself and what to do to handle the next urge.
If you've just had an argument with somebody close to you, for example, and are having the urge to self-harm, stop and ask yourself what's making you feel this way: "I feel like harming myself because I've just had an argument with somebody I love, and it's making me feel really bad." Determine what in particular makes this situation trigger off negative emotions: a certain feeling, or maybe an action? Work on reducing this issue until you have it under control or completely diminished.
Stop the self-harming episode before it begins. You haven't done all this work for nothing! As soon as you feel the urge to harm yourself, take a deep breath, fold your arms, close your eyes and relax. Tell yourself that you are not going to self harm. Get away from any objects you may use to harm yourself so it's not as easy to break your resolution. If possible, lie down somewhere. Stay like this until the urge goes, then quickly phone a help line or use another means of getting help.
As soon as you conquer one, you'll see just how doable it is. If you've conquered one in the past, what worked for you? How great did it feel after, when you got over it? Think about that feeling. Relive it. You've earned it.
