TTC 319LB

I have been TTC now for 2 years with no luck. I have all ways been big girl with irregular menstrual cycle. After starting my journey to be a mom i have change the way i eat and focued on my self more .i worked out for 1 hr 6 days a week and slowly lost 30 lbs. I have spoken with my doctor about my weight and how difficult it has been to keep it off my doctor told me i have a form of pcos and explain that i would have very hard time conceiving. After losing hope in 5 months i reach my highest weight of 319LB. I feel like a failure not being able to drop the weight and as woman not being able give my husband his only child. Any suggestions on what i should try to lose the (100Lb) my doctor requires me to lose.

PS Im starting over controlling my eating habits.