Discouraged..😕

After miscarrying twice, and now it seems like I cannot conceive to save my life. I'm not infertile and neither is he. I can have a perfectly healthy baby if everything would line up right..I just don't understand what we are doing wrong.😞 It really seems  like everyone is getting pregnant and I'm not. And I'm tired of letting my fiancé down. And myself..I do everything right. We try on the windows that are available. We. Do. Everything. Right. I don't understand ...thoughts? Tips?