Mirtazapine withdrawal symptoms experience - Help

Hi folks,

does anyone of you have experience with mirtazapine withdrawal symptoms? I took 15mg and then 7.5mg mirtazapine for 3 years and stopped it 4 weeks ago (without tapering it off). I've been feeling so bad ever since, my insomnia has completely returned - I only sleep a few hours and when I sleep more I know I haven't really slept. I feel physically exhausted every day and have had depressive thoughts since then (which I didn't have before?). my doctors say it can't be that the small dose of mirtazapine has such consequences. Anyone have experience? I have to be on vacation with friends for the whole of August and I can't do anything in my current state...