How do you keep going? 😭

How do you keep trying when month after month AF shows?! This is my 18th month TTC baby #1. I've had all tests done and there is nothing wrong with me and partner has also been cleared. Makes it so hard to stay positive and keep going when it just doesn't feel like it's going to happen. Have stopped using OPKs and the apps to track ovulation but still no success 😭😭