Mirtazapine increasing from 15 mg to 30 mg

Hi to everyone!
I am new patient with anxiety + depression disorder. I started 7 weeks ago with mirtazapine 15 mg because of general anxiety disorder combined with depression (because of heavy disease of my father).
Initialy , in very first days I felt very sleepy and my apetite got a little bit better.
And, after 7 weeks of taking 15 mg of mirtazapine, I felt a little better, but it seemed to me that there was still room for improvement. The depressed mood has decreased a lot, but there is still a lot of anxiety.

So, in agreement with the family doctor, I increased the dose to 30 mg.
So far I have only taken 2 pills of 30 mg each evening (two evenings)

I can say that right now I feel little bit worse than two days ago (anxiety increased, lack of energy, will).

Should I give the increased dose another day to kick in or should I immediately go down to the initial dose?