Birth control shots are bad, and only a solution if nothing else works. You got it, so you will have it in your bloodstream for whatever time period, but try to get an IUD instead. Birth control shots are also worse than the Pill in terms of side effects profile, so unless you really cannot trust your discipline taking meds, and want hormonal birth control, you should be on the Pill, but since you are taking psychiatric meds anyway I see no reason why you would not have enough self-discipline to take the Pill.

So in the order of desirability, if you want to be free from condoms:

1) IUD
2) Pill
3) shots far behind