<human>: Can you succinctly summarize the text in 1-3 sentences?

I really love my relationship with my SO and love him tons too, but I just don't know what we should be doing to fix our problems or even where to start.
These last few months have been getting weirder and he's been not wanting to share what he's been up to or his personal opinions. In my opinion, you need to know somebody personally at least on some level to become friends or more. However he gets in a very sour mood if I ask him about things and refuses to answer and just abandons the conversation and ignores me.
This makes it also almost impossible to try to solve problems in our relationship too because he doesnt want to deal with it. A few months ago I asked him to stop leaving the conversation and actually talk to me about his problem and I've asked him to keep doing that but he doesn't care. He just calls me nosy and threatens to leave if I don't stop. I want him to care and to feel like he can talk to me but I don't know how to or why in the first place he doesnt want to.
<bot>: SO doesn't care or want to be asked personal questions, even about our relationship and gets upset and offended easily by them.