I've been on the other side of this. When I went through this experience, I was overwhelmed, needed as much support as possible, and couldn't articulate my thoughts clearly. Sometimes I would say something, and people would get the complete wrong idea from it, which confused me. Then when I spoke to them later, they told me the exact words I said, and it was very different from what I meant.

It's entirely possible that he really wants your support, and he's bringing up moving into a new, smaller apartment because he's worried about you, and he doesn't want you to be under financial pressure as a result of him.

What my then-boyfriend did to deal with me acting so strangely was to call me every night. If I didn't want to talk, he would talk. And when I told him to stop calling, he sent me letters - if not every day, then every other day or every two days. They weren't about anything consequential, but that way I knew he was there for me.

Obviously you've been in a serious and successful relationship with this person for a long time. If his experience is anything like what mine was, he's really overwhelmed right now, and dealing with a lot of new struggles. The best thing you can do is call, visit, be there for him, and if he's experiencing doubt about the relationship, try to stick it out - it sounds like you guys are great for each other. My then-boyfriend has dealt with several of my mini-freakouts and relationship doubts, and now we're engaged, and living together for a couple of years now. Each time a lot of it was due to my mood state. Once I got out of my depressed space, I couldn't understand why I ever tried to push him away - and it meant even more that he still let me know he was there, every day, in whatever way he could.