IF Heartache Returns

All of the pain that I experienced trying for our first has returned...and it's more painful than I ever thought it would be. I didn't think that heartache would come back, after all I am a mom and that's all I ever wanted to be. I've experienced pregnancy and breastfeeding, watching our son grow from a tiny little newborn. I finally get to celebrate Mother's Day. I can join in when other mom's talk about their pregnancies or birthing stories. We can relate to our friends who have kids and not feel left out. We had 2 years of not worrying about IVF and just living a "normal" life not thinking about IF. I am so thankful for the success we've had.
But, here we are again......I thought we had it figured out. We had two failed attempts trying for our first but we went to a new clinic where it worked first try. I never imagined miscarriages, it seemed like our problem was just getting a positive. With our most recent miscarriage we saw the heartbeat at 7wks and what at relief that was, we were finally done with the rollercoaster of IF. I had tears of joy after that u/s..such a sigh of relief. We finally had the family of four that I had always dreamed of. Unfortunately, just one week later this was all taken away from us. Somehow my husband had a feeling this would be a longer struggle for a second...but I never thought it would be. Having our son does give us a lot hope, we know it can work. I never thought the pain would be nearly as strong as what I experienced having our first. I am finding it so difficult to hang out with my many friends who have more than one child. I want that too, I want to have a newborn again and I want to experience pregnancy one more time. IF is very isolating, I feel guilty once again that I am not as happy for baby and pregnancy news. I hate what this does to some of my friendships. I don't even want to know how much money we've spent, it's nauseating. I'm exhausted with the emotional ups and downs. It's just not fair. I've stopped hanging out on facebook which I used to enjoy but now it's just too painful to see everyone else move on with their lives and adding to their families. Why can't I be okay with just having one child? My husband would be okay with it, but my dream is to have a family of at least four. For my son to have a playmate...I had a sister growing up and we have so many fun memories growing up together. It makes me sad to think of him as an only child. My husband says this is our last try. It scares me to think of this cycle at CCRM not working and giving up on a second child....I don't think I could give up.