Can't get Pregnant 😔

It's been 2 years of TTC and still nothing. Me (26) and my husband (29) have gone to a fertility doctor and though there's hope of us having a baby, it's my husband who needs to take a supplement to boost his "little men". Anyway, I've notice that when I see other women pregnant I get a little upset then I start to feel really sad and thinking why can't it be me. It especially killed me when his brother, who's my age, accidentally got his GF pregnant and now the whole family is excited for her, but I can't help but feel angry, sad, even hurt. For someone who's been going out for only months, while me and my husband have been trying for a couple years now.

How could I stop being bitter/depressed about the whole pregnant thing. So many people have been saying "When your ready, God will bless you." Or "Don't lose hope." But every month when AF comes, it's just disappointment setting in. What can I do to get out of this funk. Do you know someone or have you been in this situation? Any advice will gladly be appreciated.