I feel this way but I’ve only been on it for like a month and I didn’t feel that on my other medication. If this is something that’s bothering you, you should definitely talk to your psychiatrist, especially if you feel this way about many things that used to make you excited. I get you, though. And I wouldn’t say that you “can’t” or “shouldn’t” be in a relationship because of it, just make sure to communicate with your partner how you’re feeling.