Infertility is so heartbreaking

I've been crying on and off all day today, I swear it gets harder to cope each month I get my period. 
I've been trying to pregnant for over two years now. After a year I found out my tubes were blocked and then had surgery to open them up. This surgery was 6 months ago now and still no pregnancy, even though we've been doing montitered cycles and got the 'timing' right each month.
My period started yesterday and today I had to turn down an invite to a friends BBQ because literally everyone else going has got kids, babies or is pregnant and I just can't face being surrounded by happy families and being the only one who doesn't. I used to be strong and put on a brave face but it's really starting to get the better of me now. I just feel broken! 
I'm going to see a private fertility specialist in 2 weeks, I really hope whatever they do to help works... Because I can't take it anymore, I feel so alone and sad and I'm fed up of feeling like this. 
I apologise for the 'poor me' rant but I just needed to get this off my chest somehow and not be judged by people I know. 
*UPDATE... I was starting to feel better and strong again, thanks to all the support in this group... Then my close friend dropped the bombshell that she is 12 weeks pregnant with her first  & SECOND! Yep twins!! And the best part is... It was an accident, they weren't trying, condom broke, she took morning after pill and STILL conceived not one but TWO!! I put a brave face on in her company but that night I hit rock bottom and had a massive breakdown. I couldn't stop crying all night and in the morning my partner had to help me drag myself out of bed. 
So now I'm right back where I was again and have to work on being strong and hopefull again 
My goodness this is a hard journey!
I just keep telling myself, it will all be worth it in the end because right now that's all I can do.