Advice on something- Mental Health

My Heath Worker, gave me some mirtazapine for my depression said take for a couple of weeks and come back... So I will be, but this is my third week on it and no change in how I feel, I just feel more depressed, more anxious, more tired and drained and can barely get up to do anything let alone study or work.

If this only me that has had this trouble? And do you think I should relay this back to my Dr when I see her/him or not? Do you think I am being a idiot and just need to accept this is how I will feel now I have a stupid mental health illness.

Finn x