Why am I not getting pregnant ?😭 😩

AF is regular . She comes every month , around the same time , lasts four whole days ... I use ovulation tests , I use pre-seed , I use Pregnitude , I take my temperature , I track , track , track , and we BD throughout my fertility window and then some ... I'm losing hope ... What else can I do? What am I doing wrong ? I was hoping my SO and I could concieve without fertility treatments . We gave up once , after a year ... We are about to give up again . I just feel so bad . Like , why can't I give him the family he wants ? I know he doesn't think I'm less of a woman , but I sure as hell feel like it . 
My biggest dream in life wasn't to be a doctor or a movie star .. My biggest dream was to be a mother , be a provider , have a family . I think that's just the Southern in me . I look forward to the busy schedules and the early mornings and late nights . I look forwards to the ups and the downs of motherhood . Ya know ? I didn't play teacher or Doctor . I played mommy! And I made sure I was always the mommy! lol . I'm even in the early education career field . This was my goal , but ... 
Maybe I'm not meant to be a mother . Although that hurts to say ... On that note , I'm the one who talked my SO into wanting kids . He never thought about having children intil  , as he says , "the excitement I brought when I spoke about children , won him over." ... Now he's waiting for this family that I don't think I can provide . Honestly , I don't know if I could disappoint him like that ... I don't know if I could ... AF came late this month and I just seen how happy he was ... He was kissing my belly and everything , and I cried so hard , I was so scared to tell him that AF came . We are engaged , but I don't think I could go through with it if I can't make him 100% happy . I know he'd be happy with or with out , but I honestly think he has his mind and hopes set on a family now ... This is the hardest thing I have ever been through ... 
They trick you into thinking it's so easy to get pregnant at a young age , but never tell you how hard it is when you're older ...Â