I feel so broken (vent)

A year ago I thought this would be easy. I thought, because I'm young it'll just happen. Every cycle is starting to get harder, the breakdowns come faster and sobbing becomes more frequent. I feel so overwhelmed with stress most days because all I can think about is, "If it doesn't happen you're broken, you're a failure and your partner will be let down". I feel so alone in this, I can't talk to friends or family and I feel like I'm putting down my fiance. I can't discuss these feelings with my therapist because I just met him and don't feel comfortable yet. Its hard to just start over the next month, I want to be hopeful but it hurts to. I just need a friend that understands.