When will it end?

I apologize for the dramatic title, but I don’t really know how else to phrase this. I’ve been self-harming, on and off, since I was a child — maybe 11 or so. I have been addicted to drugs, alcohol, so on and so forth. I’m 21 years old and relapsed recently for essentially no reason and am just baffled. When will it stop seeming like an option, mentally? When will it stop seeming reasonable to resort to self harming? It just seems so childish to me now and I cannot shake resorting to it in moments of utter duress. Thanks.