I feel guilty when I open up
Why would you feel this way?
It's like I'm offering you something that I can't afford to give
It can be tough to truly open up to people. Make sure you're giving your honest feeling when you do open up, and that might help with the guilt. When you get used to sharing your feelings the guilty feeling might go away.
It hurts when I share my feelings.
Well, the more you open up, the easier it gets. So keep at it.