Please read, anyone feeling the same

Feeling heartbroken, if you have been following me you already know my doctor gave us 4 more months of ttc with letrozole. My period arrived today which means another failed attempt at our family, to top off my heartbreak my coworker announced that she is 12 weeks pregnant I honestly don't know how I am going to be able to see her everyday at work without feeling like crap. Why is ttc so hard, I mean I got pregnant in 2011 while on bc had a miscarriage and haven't been able to conceive since. All I can do is cry it's been almost 4 years 😢