Adhd meds stopped ‘working’

I’ve been on methylphenidate since November and it doesn’t feel like it does much, in fact leaves me with a low mood in the afternoon (even worse when I use a top up!) I’m on 54mg of slow release and have instant release top ups. I have tried Elvanse but it made me anxious. My mood is a bit low to be honest, even with added lexapro. I feel exhausted all the time. I’ve had extensive blood tests and they came back good. Not sure where to go from here! Has anyone else had this issue? I think I get a review in November but no access to psychiatrists until then.