I understand ur urge. Why do u feel that u need to punish urself for eating brownies?? That is kinda coincidental cause i just ate a big brownie and felt guilty as hell too!! But Iam thinking that it maybe wasnt a good idea but tom I will do better. Tom i will be a little extra careful.
Ur not gross!! It is natural to want a treat and since u feel bad today maybe u deserve to treat urself a bit. Cutting is not gonna make the brownie go away. Neither will it make u feel better. Give it some time and try to think about something else.
Do u have a favorite place to go? Even if it is an imaginary place, go spend some time there and let urself go and relax and meditate. I do control breathing while saying " beautiful peace" over and over while inhaling and exhaling. It works wonders. i imagine the bad cutting feelings as a literal object and then imagine that object melting away. I meditate on it for at least 5 min. When iam calm i think about the urge to cut and usually the urge is gone.
Please try these things so u dont cut. If u do please be careful.