My girlfriend said she needs some time off, but I don't want to lose her. I'm really sad, but I don't know what to do.

At a point in every relationship, a person pulls away to decide what they really want. At this time, the other person has an important decision to make: do I give her space, or do I pursue her? If you pursue, she will probably only want more space because she'll feel like a caged bird. So, the worst thing you could do is to try to snatch her back. Be strong, confident, and independent. She can't be attracted to you if she pities you and feels sorry for you because you're lonely.

When you respect her wishes and show her that the door is open to leave, something good happens: Instead of asking "How do I get out of this?" she is free to ask herself, "Do I really want to leave?" This needs to be her decision. If you want, you can tell her in person that she is free to have this space, or you can write it to her in a letter. If you do write a letter, wait a few days to send it, because you may write something while under intense emotions and then mail it, only to wish later that you could have said it differently. After it is sent, show her respect by giving her freedom, and if it meant to be, things will work out.