I'm so stressed & tired I give up 😥

I see everybody on here all happy they got they positive test when I can't get not one smh I just really believe deep down in my heart I can't have kids . I'm stressed I wanna cry I have sleepless nights I just don't know what to do but give up. Because it's not happening. My periods are very irregular I don't know when they are coming just know it's the middle of the month around the 13 to 18th io don't know when I ovalate of if I do at all I'm just so tired of trying I don't know what to do