Can anyone help

No idea what I'm doing wrong but having another baby at this point seems impossible I'm probably more likely to find a unicorn trying not to stress but I just seems like I should be able to do this I've already had one but we wanted another and now it seems so hard when getting pregnant the first time was easy I'm taking vitamins out the wazoo and drinking so much water I feel like I'm gonna float away sometimes I'm eating healthy and exercising I just don't know know what else to do

Sincerely frustrated