I can tell you I have never heard of anyone on birth control have a problem because of PKU. It could merely the shot makes you feel that way or your body can be rejecting it. The easiest solution is to stop being closed minded about other birth control methods. Just because your partner doesn’t like to wear condoms doesn’t mean he shouldn’t. Knowing what you go through with your shot he should be willing to wear one. I would say go to your clinician, make sure it’s not PKU, because if it IS you need to get off that shot RIGHT AWAY. Wish you the best.