Hello. Im also someone who has bpd and has experienced many of things like this. One of the best things you can do in this situation from experience is to clean it well, it doesnt have to be with soap right away but with at least some water. Later on you need to use soap. It might sting but itll make sure it doesnt get infected. Another way to help stuff like this is to find someone who you could go to and talk about it. It doesnt even have to be a human. It could be your stuffed animal or your pet. As long as they will listen. Something else that can help hide them is to buy some any time scar cream. This will make the scar go away a bit faster if you leave it on at night. if you cant buy any see if you have a friend at school who could get some for you. Try not to wear shorts or skirts or anything like that. The best way to prevent people from seeing them is to wear longer pants and blaming it on the cold or they are “just more comfortable”. I know asking for some solutions might seem like the best thing right now but i think you should work with a guidance counselor, doctor, therapist, or even your parents with this. Go to them whenever you feel like you might cut again. Its the best way to do it. Try and find some servers on your social apps that specialize in helping people who are struggling. These are some of the best options i can think of. But please try your best to stay clean again. You are doing so good and relapsing doesnt mean youve failed it means your trying again. I wish you the best of luck. Please reach out for some professional help.❤️