It doesn't sound good. If he's telling you not to buy him a birthday gift, the doctor probably gave him a prognosis. As his girlfriend, you probably really don't have any rights, but out of decency, he should tell you. However, it's probably really difficult for him to be decent right now knowing that he probably doesn't have much longer on this earth and that his last days are going to be very painful. What are his religious beliefs? Does he believe in heaven and hell? At the end of life, people will have a lot of concerns, and sometimes they just curl up into themselves and try to keep everyone outside. It's an effort to protect those around him, but it is hurting them instead. Let him know that you love him, that it will be hard for you to see him this way, but that you want to spend as much time with him as possible. Home health hospice could help.