You adore your boyfriend. If you're like most women in love you can't get enough of him. Whatever time you aren't spending with him in person or on the phone, you're longing for him. Sounds just like you, doesn't it? You'd give anything to spend the rest of your life with the man but you have recently come to the realization that he's not feeling the same things. He may have told you that he needs some space or room to think. If your boyfriend wants time alone it's imperative that you do certain, very specific things to ensure that his temporary need for some space doesn't turn into a long term break up.
When your boyfriend wants time alone the worst possible thing you can do is push him to change his mind. A man who is feeling distant will only become more so if the woman he is with won't let him go. He'll view your behavior as a sign of pure desperation. He'll run in the opposite direction as fast as he can and he won't look back. You are showing him, through your behavior, that you don't value him enough to give him what he needs. You are essentially demonstrating to him that your needs matter much more than his. No man wants to be with a woman who is that selfish.
If your boyfriend wants time to think or he expresses a need for space, give it to him. You certainly don't have to have a huge smile on your face as you push him out the door, but be understanding and cooperative. The man is struggling at the moment and if you can show him some compassion, that will help him see why you are the perfect partner for him.
It's a good idea to leave him alone for a bit once you two do separate. Absence can be a powerful force during the most tumultuous times for a couple.