Anxiety: please read

This immense anxiety has only emerged in the past couple months or so. Ive been in a serious relationship for three years now. I have been on birth control, first the shot, now oral , for three years and have taken the pill accurately and correctly every dose. Recently I have been having digestive issues, daily diarrhea, constant abdominal bloating and discomfort. I have been put on a diet plan because the doctor believes I have IBS. The last time I had sex was the 20th of feb. since then I have taken 7 different pregnancy tests, all in which came out negative. I have a irrational fear I’m pregnant, even after getting two periods and all negative tests. I even got an ultrasound and urine test done from assumed endometriosis(later came back from both as completely normal) I cannot have sex anymore because I am terrified of getting pregnant, and I still think I am right now! It’s to the point that I am sick to my stomach with anxiety daily. Should I tell my mom? I’m 19 and sex isn’t a topic we usually talk about. Do I need to see a therapist? It’s at a point where my days are filled with worry and constant anxiety about any symptoms I get.