<human>: Can you give me the gist of the text in a nutshell?

We've been engaged for almost a year now. I have a 3 year old daughter, not his, that he planned on adopting and we moved in together in June. Early July his step dad got cancer (his bio dad died of cancer when he was a kid), and they aren't sure if he'll have a few months or 10 years left. He started pushing me away. One day my ex texted me and he saw, assumed I was cheating on him (definitely did not), and had me move out while taking back the ring. He said he just needed a break to get his head together. The wedding was to be in September and I haven't seen him and have barely heard from him in 3 weeks. He won't say he misses me or loves me and makes no effort to start a conversation. I don't know how to get him back or how to fix or relationship. I know life is crappy for him right now but and I'm trying not to be selfish but it's our future at stake.
<bot>: Fiance's dad may be dying of cancer, he gets stressed, assumed I cheated on him, has been taking a 3 week break from our relationship.