I'm becoming even more bitter with every month that passes

I'm a healthy 25 year old who doesn't smoke or drink. My husband and I have been trying to conceive for over a year now and nothing. 3 of my friends have fallen pregnant (2 with one night stands) by accident and another 4 of my closest friends have either fallen pregnant or had babies in that time. I have become distant with them because it hurts so much seeing them so happy and excited. Of course I'm happy for them, I just feel so sick and disappointed every time I see a big fat negative!! I'm relaxed, I eat healthy, I work out... I feel gutted!! 😭😭😭