Never my time

My husband and I have literally tried it all. All the weird little things that you know probably won't help but do it anyway, always doing the deed on ovulation, I tried clomid and maca, we both take vitamins everyday, and we both already have children from previous relationship, so why? Why us? Over 3 long years we've been trying, we did the whole "taking a break and it'll happen". And still nothing, always nothing. I've watched 2 of his sisters have multiple children, and now a 3rd is having twins. I don't get it, I just don't get it. 😞