What position would I play?

You should probably play shooting guard. I think you would be better for that than point guard because if you want to be a good point guard, you should probably work on your dribbling. A point guards dribble should be better than okay. You should probably gain some muscle weight though by hitting the weight room more often and eating more. To gain muscle, you need to eat lots of nutrients and get enough fiber. I guarantee you if you gain musce weight, your shot would improve a little and you'll be able to have more stamina.