Got called the worst thing in my (20F) life by my boyfriend (23M)

Boyfriend and I have been together for 2 years. Got into a stupid argument which escalated into a massive fight because neither of us could let it go earlier this morning. Some yelling and blaming was done on both parts but I refrained from any name calling or taking any irrelevant hurtful jabs. We were yelling and stopped for a second and stared at each other when he said to me "You are cancer in my life." My mom had stage 3 cancer for 4 years. He knows about it and he knows it's a word that holds a lot of emotional ammo. I cried. A lot. We fought a little more, but I was too tired and cried out to keep going and he had to head to work. He's been at work for a few hours now but ive been sitting in my bedroom just feeling kinda numb after hearing that.

How do I deal with this? No one has ever said anything remotely this hurtful to me before. Is this forgiveable? Do I talk to him about this?

Tl;dr: boyfriend of 2 years said im cancer to his life. Don't know how to deal with this. Advice/opinions welcome. Thank you.

EDIT: I posted an update in the comments below.