Totally get the frustration.
Especially in the first few months... when you expectations and hopes are high and you really still think that unprotected sex = baby.
Obviously don't wish this on anyone but truth is with time it does settle a little bit and as the months pass and you still aren't pregnant even with all the timing opk temps trying hard etc..
You will learn to chill out a little and more importantly to adjust your expectations.
You still get sad when AF shows up but you will move onto your next cycle ...
As it was correctly said before... this baby business really depends on too many things and there isn't one rule or probability. Even for one couple doing the same things it won't work the same way each time.
Each couples is different and some will conceive with one time effortlessly, some will take 3 months, some 2 years, some more, some will have miscarriages, some will have easy pregnancies some will have tough times, etc etc...
I think the lie is just that we were made to believe that fertility is a textbook thing. But it's the complete opposite. More like looking into a crystal ball... (unless you have a medical condition obviously and need assistance)
So i would say just try to think of the bigger picture and not expect a baby in 9 months every time you have sex. But rather see this as a process that could be more of a marathon...
Be kind to yourself and try to focus on positive things in your life while ttc. Don't make your life revolve around it as much as you can...
Think of it as a side project otherwise you will make yourself miserable. Talking from experience...
That being said i do wish you are just a couple of tries away and it happens soon for you!! X