How do I fix the problem I created?

Last night, something came over me and I cried for hours. Lately I've been feeling overwhelmed with the pressure my family has put me under. I'm the middle child, but I get treated like the oldest because my older sister is uncooperative with everyone, and is just flat-out rude and disrespectful. She's graduated and has done nothing with her time, and complains about it. So, Im the one who has to set the examples for my younger siblings, I do most of the cleaning, and I try to be as nice as possible despite my parents actively mocking me every now and then...... Back to the main point. I cut myself last night. I was a little disappointed to wake up this morning, but now I have no idea how I'm gonna hide this from my parents. This isn't my first time, but I would only cut my legs before, and they are never really visible. So how do I hide the very obvious lashes on my wrist and arms? I cant stand therapy and really don't want them to put me back in. Can someone please help me???