I started dating my current boyfriend around 4 months ago but we had been acquaintances before that as well. Around a month ago he started going through really depressive phases. In the whole time I'd known him this had never happened so I didn't know how to react to it. I feel like I let him down. He often does not want to talk to me or invest time in any plans that I make for us. Sometimes it's hard for me to differentiate his depression and plain ignorance. How do I help him and our relationship through this?