Don't be irresponsible. If you are that uninformed about what is involved in being a guy with CF and the complications of reproduction, then you have NO business even thinking about fathering a child with your girlfriend.
I realize you probably want to experience the closeness that comes from a fulfilling sexual relationship with someone who cares about you, but at your age and in your situation, unprotected sex is FOOLISH, DANGEROUS and SELFISH.
When you are better able to cope with having CF in your life and when you are in a mature, committed relationship, then and only then is it appropriate to make steps toward being a parent.
If your girlfriend is mad because of inability to have a baby with you, then she is equally immature and selfish. The two of you can potentially cause a lifetime of hurt for a child whom neither of you can successfully parent.
Keep it in your pants, kid. And that girlfriend of yours should keep her knees together.
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