Hope I'm not intruding.. I'm so sorry for how you feel. We felt that way before BFP #1 so I understand how you feel. Just wanted to give you my sympathies and tell you not to give up hope.
Have you seen a specialist at all? They say if you haven't fallen pregnant after a year to see a specialist to rule out any issues that maybe stalling your BFP. Falling pregnant is easy for some woman but others need help or need to know their cycles PERFECTLY. I recommend joining a site like fertility friend and starting a chart. Buy tons of cheapie opks and hpts.. I always used wondfo brand and never had a false positive. Buy a GOOD bbt thermometer and chart as well your temp. Even if it seems way off. You have to buy a bbt thermometer not a normal one. Same time every morning after a solid amount of sleep. Chart any and all symptoms, opks and temps. Don't give up you'll start to see patterns that way you know when to have sex for perfect timing. Also taking your charts to specialist will help them immensely.
After two years ttc and seeing a specialist who ruled out any physical reasons we weren't conceiving I was prescribed clomid. Fourth cycle of that I feel pregnant with #1. #2 and #3 pregnancy happened ridiculously fast for us having had so many bfn cycles with #1! I think it had to do with knowing my cycle perfectly now.