Stay with it, mate. Stay on target. The kind of math you have been exposed up to the 9th grade is not like calculus or physics! Not at all. You need to learn a completely different way to think, and who knows? Maybe this is your time to shine.

Also, you don't need a 4.0 for anything other than medical school or law school–stuff like that. Don't over stress on what you think your grades should be. Work hard, pass your classes, train your mind, gain the knowledge you want and put it to work. There are an awful lot of people who have been successful with 3.0 or 2.0 GPAs. I am one of them.

A career involving the cosmos is not a 100% overlap with NASA. There are a lot of paths to the stars.

Keep at it!