Invega Sustenna is one of the few ap's I haven't been on, so I can only generalize from my experience with the number of ap's I have taken. I'm pretty sure my sex drive would come back, in time, if I got off my med's, but I've learned through hard experience that I can't get off my ap's. I still have a sex drive, though, just not as strong as it was.
I feel like if I got off the med's for my heart and for my knee I would ejaculate more sperm when I have an orgasm. It's not really the med's for my heart that are doing it. That stuff is omega-3 fatty acids. My doctor feels like that is good for my heart. I think it was the anti-inflamatory med. for my knee that reduced my sperm. Like I said, I'm only going to worry about that if I decide to have a kid, which is unlikely at my age.
It takes a pretty good while for all these med's to leave your system. If you had patience and gave it time your sex drive would probably come back if you got off the Invega Sustenna.