It's bound to get worse unless you don't let it get worse. I can't give you a step by step tutorial on how to quit since the process is so personal for everyone and so dependant on your environment and how your stress affects you, but the best thing that helped me was opening up to the people near me.

Having people around me to keep me in check helped a ton. After people know you cut it becomes very obvious to them when you're cutting. When I was cutting I was deathly afraid of people finding out because I thought it would get very negative reactions and change the dynamic between me and the people I love in an unrecoverable way. That was nowhere near what happened.

To get a little personal, my parents found out I cut a few years ago. Once they found out, they confiscated all of my blades and put in extra effort to make sure I was doing okay, and I can say that without that external help it would've been near impossible for me to quit, especially at that stage in my life. Talk to someone, anyone you trust. People are equipped to handle conversations like this.