Boy problems and depression

So I've recently relapsed into severe depression and have been self harming a lot. I know it's horrible and I am working on it. There's a boy I've had feelings for for years and we dated for a short while. Recently we've been talking more about sex and I feel attached to him again. But every time he says something that upsets me (by not answering or something) I get a major mood swing and become seriously depressed and have self harmed as a result. He doesn't know this. I haven't told any of my doctors because it feels stupid that I react this way simply because of a guy. What should I do?