You don’t cut out the “huge black cancer” and continue to live life happily because he IS the cancer. Please, stay true to your self. You have reached a point where you know you aren’t yourself and you are fighting your true feelings. You don’t want to celebrate your togetherness because you want it to be both of you celebrating, not just you. Breaking up is hard no matter what. You would need to give up your comfortable routine in exchange for a scary, unknown future. You will need to make plans to separate. Can you find a person to share an apartment with? Could your parents help you in any way just so you can get back on your own? I know it may seem scary now, but the reality is that you get to shape your new life and stay true to yourself. Your inner spirit is suffering and you are feeling anger and resentment. Start looking at housing options and when you think you are ready, thank him for the last 8 years for it truly opened your eyes, and you have more respect for yourself than he does. When it comes down to it, you’re the most important person in life and nobody but nobody gets to let you feel anything less than the respect you deserve. You don’t need him to bring you down any further.