For me it was initially effective because it's an opportunity to vent judgement-free to people who at least pretend to listen to you, though when my life circumstances became way worse shortly afterwords due to physical, real world issues the CBT was useless. Basically therapy is a game of trying to convince you that you deserve to be happy and your current sadness is due to mental blocks and self-sabotage that they'll try and clear. They'll probably go through the mechanisms of how you rationalize your emotions, try and spot negative thinking patterns, tell you that your alcohol inhibits your ability to recover and some strategies to pick up your health again; they can also refer to psychiatrists for medication. If your current hysteria is due to non-mental, real adverse circumstances (abusive family you're stuck with, homelessness, getting fucked over by the system, severe bullying) they can't do much for you other than listen or get authorities involved if they think you're at risk of something happening.