PCOS, can you have a milder form?

my doctor believes I have PCOS, I had lab work drawn & my testosterone was 0.22 (normal) FSH 8.1 (normal) the ultrasound of my uterus showed a thinned lining (normal, I had just finished my period) & my ovaries didn't show any small pearl like cysts & weren't enlarged. BUT my insulin level was 173 (extremely high) I have periods every 30-40 days they are painful & not always in a timely manner. We are still waiting on my LH levels. Is it possible to have a milder version of PCOS? my doctor seems to think metformin will get the elevated insulin under control which will in return level everything else out. I'm only 22 years old, I am overweight & suffer with chronic fatigue as well as the inability to lose weight I really hope this helps!