i think i need a therapist

my health problem seems to have come back but every time i get checked out by a doctor, they say everything seems fine. but that's the thing, even though i agree with them (my blood pressure and pulse hover over the normal range and shouldn't be affecting me), there's that nagging feeling in the back of my head that i am not fine at all which i think is contributing to my insomnia. i think i have an anxiety disorder. for the past week, i've been dreading being left alone at our place. there's always these negative thoughts hovering in my head. "what if something happens to me right now?" it's getting so bad that i even usually have the phone close at hand "just in case" i have to call 911. see, even just reading that makes me think how fuckin ridiculous my mind is being. i think i need a therapist.