The only one???

Am i the only one who's never been pregnant before? Im 28 yrs old and never had a BFP in my life! It's so stressful, depressing, tiresome. Sometimes i feel like what's my purpose here on earth if i can't give life? Im afraid my fiancé of 2yrs will eventually leave me one day because of my infertility issues. Everytime A.f arrives after 42 days or more i feel like its the end of the world for me......