Hi. I'm Experiencing What I Believe Are The Side Effects

Hi. I'm experiencing what I believe are the side effects of Mirtazipine which was prescribed to me for help sleeping. My feet and hands ache and are somewhat swollen; hands and feet, etc. feel like they're falling asleep all tingly; joint and muscle pain; stiff neck, etc. I noticed these side effects around Day 22 and STOPPED taking it. I am still miserable 10 days after stopping and I'm wondering how long till it's flushed from my system. I'm drinking as much as possible. Is there any other way to stop these awful side effects?? What else can I do to help myself?
Thank you!