Is what people give me all they are willing to give me?

I am not very good at asking for more from people or at expressing my needs to people. I am learning to be better at it, but I do have this deeply held belief, I think, in spite of knowing better, that what I receive from people is all they are ever willing or able to give to me. I feel as though they will be unwilling to give me what I ask for, if I ask for more, and that I will be left with nothing in the end, somehow. I'm wondering if there's a way to train myself out of this, but I don't even know what I want from people! Often, all I want is some time alone, but I'm not even willing to give that to myself. I schedule too much in advance. Oh well. I think I'll go make some nighttime tuna salad now.