Hi there
I know your frustration!
Clomid worked well twice for me. I was diagnosed with PCOS when i was 25 TTC#1. Clomid is the only way that i O. Otherwise i never have cycles at all (which is fine when i'm not TTC!!).
A GP can't prescribe clomid as far as i know. I think your GP will refer you to a fertility specialist or OB/GYNE.

Good luck xx