I'm polyamorous, my boyfriend is not, and this tension is making me miserable

I think I need to break up with my boyfriend. I love him so dearly but the only options are break up and be poly or stay together and hurt my own feelings when I crush on others. There is no way he wants to do polyamory, and every option makes me feel terrible. It doesn't help that I relapsed on self harm and drugs....I know it's bad but I just am so distressed and don't know what I'm doing anymore. I'm desperate. How do I compromise, and is it even possible?

If a relationship is making you feel desperate and distressed to the point that you relapse into self-destructive behavior, it's not healthy for you to be in anymore. Sometimes "love" isn't enough - sometimes two people are mostly great together, but one major issue makes them not compatible in a relationship. It's heartbreaking and frustrating to have to break up when there are still things you love about being together, but it sounds like it's necessary in this situation. 

Please reach out for help with the drug use and the self harm - you don't deserve to be this miserable, and you do deserve support through this difficult time. Not having the freedom to live into who you are as a polyamorous person is really unhealthy for you, so you need to start taking the steps toward a healthier relationship arrangement, even if that means no longer being with this current partner.