I understand your situation. I had to go through something very similar to that. I knew this guy who seemed pretty cool and liked to do voice-acting stuff. So we would do projects together and read things together and just have a good time. He even introduced me to some awesome people and we all hung out together. Then he started telling me about all his problems. At first, I was delighted. I absolutely love helping people and so I listened and tried to help in any way that I could. Things were going fine and we were like brothers. He then revealed that he had a huge crush on me and hated my boyfriend, even though they haven't spoken and he only thing he knew about my boyfriend was... well, that he was my boyfriend. He continued to flirt with me, and I really didn't know what to do. I kept trying to dodge around it, kept trying to say that I just saw him as a brother, kept trying to keep everything peaceful. But that's where the emotional manipulation came in and he started talking about harming himself more often and how much I hurt him and how much he needs me and I was pretty much playing right into his hands. Though he was like a brother to me, he was a danger to my relationship and my emotional state. My grades were going down the drain, I was more irritable and it brought out my depression a lot more. So I dropped him.

It didn't feel good. It was probably one of the hardest things I've ever done. Because I knew that before all of that craziness happened, he was depressed and he did need support. But things just grew out of control and no matter what kind of support or kindness I gave him, it always made him feel awful which in return made me feel awful. It wasn't good on me emotionally and, though the situation isn't exactly the same, I bet this isn't good on you emotionally either. If you really can't take it anymore, drop them before it leaves mental scars on you. I know it won't be easy, but it'll all be worth it in the end. I promise. We're here for you!