I think the only issue right now is that you may be trying to progress too fast. Get straight airs down comfortable before trying spins...
Sound advice, but my experience was the opposite. i could land 180s all day before i could land a strait air. The only reason i could think of is because during a 180, im concentrating on the rotation, spotting the landing, and it generally keeps me occupied while in the air. When i was just trying to strait air over a jump i would get Air man arms and beef it because i would get unstable.
Air man arms: