Doctor says levels are normal, what were your levels?
You have dropped weight, what do you weigh now?
50mg every two weeks is not much at all. I take 150mg once a week. You're shutting down whatever natural test your making, and replacing it with a very low amount at a long interval. I think a 100mg a week is standard. You need to be injecting at least once a week, if not two times a week to even out your levels and stop the roller coaster effect.
You need to have your estrogen levels (E2) checked also. I'm not sure what else you need to be looking for, other than maybe a new doctor. Or take matters into your own hands and start buying from a source on this board.