Do you ever feel like enough is ENOUGH?

My husband and I REALLY REALLY want children and we've been trying for so long now but sometimes (like right now) I feel like enough already...We are "trying" and "trying" (put in quotes because I say having unprotected sex period is trying even without the intention of making a baby...even if you try to pull out or whatever) and nothing. I just don't have it in me anymore to get my hopes all up and go BACK on that emotional roller coaster! As much as I want a family it's depressing to try, try again seeing friend after friend parade by with baby after baby....I have 11 (ELEVEN pregnant/just gave birth friends...ELEVEN). I am NOT jealous but when is it my turn?? My husband and I haven't used birth control...condoms or pill in YEARS...maybe even 4 years. This is ridiculous! I just don't have it in me to do it again....I just don't... :( I'm a mess. I'm depressed and as much as we want children....I don't think I can handle the heartbreak anymore. And no, we haven't went to the dr....I'm afraid of what he/she might say. I've had a lot of "feminine problems" in the past and my mother also had difficulty getting pregnant too! Please just give me some hope and NO MEAN COMMENTS PLEASE and PLEASE don't say "don't stress" I have NOT been stressed until just recently.