I feel like a failure, does anyone else feel like this?

Three years of getting my hopes up, begging and pleading for a positive, I have pcos and this month I was so sure! I’m late for my period my boobs started hurting weeks ago and I got acne like never before, so I thought my periods coming again, but I had sex when I ovulated after two weeks of periods symptoms nothing! So I was convinced I’m finally pregnant I prayed and hoped but just another negative now I think it’s just because I didn’t use fmu, but it’s so clearly negative, im thinking that weight loss is the only way, and have told myself that I need to show God how much I want a baby, but weight-loss is hard and I’m failing myself because I would give anything to carry a child and have children, but I can’t stick to keto I don’t crave sugar, or unhealthy foods I only crave carbs so it’s incredibly hard . I’m in the verge of tears because I want this so bad and I’m failing 😩😥, anyone conceive with pcos? And did weightloss have a factor?