Anxiety about boyfriend’s health

I’ve been with my boyfriend for over 8 years now and recently I’ve developed some serious anxiety about something happening to him. I’ve had anxiety and ptsd since my childhood but recently especially with the flu season and some recent health scares I’ve been panicking and worrying almost all day about his health. Does anyone else get uncontrollably worried about their significant other getting sick or hurt? How can I get myself to chill out?