I'm giving up!

I'm 34 and I just married the love of my life in April of this year. I'm afraid that I lost my fertile window being this age and not having any children yet and I feel like such a failure every time AF comes! We've been trying since May and nothing yet I am so done with opks, pre-seed, bbt, cervical mucus and everything in between! I am a proud Aunt of 4 so they will be my children I guess. I know it's only been 6 months but I  can't deal with the constant disappointment every month! My sister got pregnant quickly at 34 and 37 but there must be something wrong with me that I can't seem to do the one thing I've dreamed of for as long as I can remember. I taught preschool for several years and now I'm a social worker so my entire life has been dedicated to children and I can't even give my husband a child 😢 I'm done so done and if one more person asks me during the holidays "when are you having a baby" I'm going to scream!!