I feel like im so boring and my friends are disappointed

I used to be really happy and energetic and now I’m the same but I’m just.. different. My friend was asking me to so something and I said no and she said me a year ago would have done it. I feel like I’ve become so boring and dull and I don’t know what to do. I think it’s after my adhd pills but i dont think thats the problem. I feel like such a let down and I wish i was normal again