anxiety and pregnancy.

this is my third pregnancy. i have a 6 yr old and lost my angel in 2015. this pregnancy (22wks) has heightened my anxiety so much. i can get myself together by sleep or tasks but it is still there in the back of my brain. my SO and best friend try their best with me. to calm me and talk some sense into me. my anxiety is triggered by 'what ifs'. the thoughts run constantly thru my head all day. i just need to scream sometimes. mainly because i know my thoughts are ridiculous. anyone have any ideas to get myself to think more of the present and not the what ifs.