Low dose medikinet does nothing, higher doses make me anxious and stressed

Hiya, I've been diagnosed for about 6-ish months and have had medication for 3-ish months. I'm currently on 15mg short release medikinet, which I take maybe a few times a week. I must admit though, there have been days or weeks recently where I haven't touched it, just because it doesn't really seem to help enough to justify it. Initially, it did seem to help, but I'm like 90% sure that was just placebo cuz it seems to be less and less effective as time goes on. I've spoken about this with my psychiatrist, and she recommended trying a higher dosage, so I did both 20 and 25mg doses, but they made me very anxious and stressed and overall rather uncomfortable. I'm stuck now in a position where I'm taking it just in case it happens to do anything, even though it doesn't really feel like it

What should I do? I've heard that there are other meds available, but I don't know what to ask for. I haven't spoken with my psychiatrist in a month or two, so I might bring it up in our next meeting

I've also heard that the jitteriness can be caused by habits about when/how you take the medicine, which might have something to do with the anxiety, but I haven't seen any concrete advice on what to do about it