AIO. My bf keeps talking about his beliefs while I’m trying to grieve

My(F20) twin sister died, and I’m shattered. I needed comfort but instead today when I was having a breakdown my boyfriend(M23) said ‘heaven is the best place for her’. This really tipped me over the edge so I went for a drive in tears. All he has been talking about is gods plan and these messages he sent me when I wasn’t picking up the phone are proof. I’m suffocating. Would I be overreacting if I left him?? We have been discussing marriage before my sister passed away.