Perhaps a male's perspective would help with this....
Your situation is one where you are in love with a man who is clearly overwhelmed and stressed. He comes to you of his own motivation and tells you that he wants to back things off a bit as things have been too intense. You, who are clearly very in love with him, feel torn; you know he is overwhelmed and stressed but yet this man is wonderful and you can't really deal with the thought that this relationship could be going in a direction such as this.
What to do? Do you back off Do you press forward?
Men are much less complex in many ways than women. We tend to be more simplistic in our views of complex emotions and circumstances and sometimes this drives the women in our lives overboard. Our reactions, if done by a woman, would mean something totally different than if a woman said or did them.
The good news. I believe that B is simply feeling too overwhelmed and pressured to deal with the complexities of a relationship. For a woman, that typically means in so many words that she is done with the relationship and is telling the man, we are done or lets just be friends.
Men, well...most of us are not this forward thinking. We tend to need space when our emotions get the best of us. This almost never means that the relationship is over, just that we need some space and time to ourselves. Usually it means that he needs some weeks to recover and recoup and to get himself into a plan. These plans need time to work out and as such often require no contact. Simply, men withdraw until they are ready to reengage and respond.
I think that is exactly what is going on here. B needs some time and he needs to see that you are totally willing to give it to him, and to not pressure him in any way. Some men do this, especially those who have been through bad relationships before as a test of character and expectation for the woman they are interested in. The way to pass the test is to keep in contact with him; text him, even call him once in a while but to do so with a focus on fun and lightness. I have a feeling that the world sits on B right now and one more serious thing would be too much. So, he created space.
He clearly has feelings for you. Otherwise he would have been far more blunt and purposeful in his actions. Instead he gently talked to you and showed genuine emotions with you. This is not common at all in males who are not "into" someone.
Give him space. But, in your contact with him, have fun with him. He needs this and in time, I strongly believe he will be back with you, fully. For now, this is a respite for him, a time to refocus.
I know you are scared, but I think you have little to worry about. The signs he is showing here are good ones and he seems a decent man. He likes you. That is clear. He is just has too much serious input in his life right now and needs a more casual approach. Stick with him, but let him set the pace. I see this working through. Steven