Anxiety and depression

Hello everyone, 

I require some advice because I no longer know what to do. 

My boyfriend has anxiety and depression. At the start of our relationship everything was perfect. When he told me about his anxiety and depression he was worried I would run and not want anything to do with him. I are assured him that this was not the case. He was very surprised that I stayed. 

In the last month or so something triggered his anxiety really badly. I've tried my best to understand what it is he needs. I've asked him what it is he wants but his response every time is "I don't know". He explained to me that when he's like this, he has no feelings, numb inside is what he said.

He worries that he's a burden to me, causing me pain, bringing me down with him and not being good enough. I've reassured him every time this is not the case. I even suggested space for a while but that didn't work.

He pushes me away and goes quiet on me. I feel I'm constantly going round in circles, feeling useless to him and whether or not I'm coming or going.

I asked him straight out of he wanted me to leave, which he said no he didn't. This has left me so confused. He doesn't want me to leave but doesn't know what he wants. 

He hasn't replied to my last message. It's always me to break the silence and ask of everything is fine. But this time I've decided not to message him first to see if this time he will reach out to me. However, I feel this will keep me in limbo for a while and me waiting for him to message back, whenever that will be.

Sorry for the long essay. Any suggestions will be appreciated. I've ran out of ideas on what to do now. I care for him too much to just walk away

 xxx