Oh, OP, sorry to hear this. It seems, though, that you've got a very positive, "work at it" attitude, so I'm sure you'll get there in the end.
I'm going to say something a bit weird now, so apols to all if it's wide of the mark or out of order in anyway.
OP - where do you stand on dogs?
The reason I'm asking is that DS formed a v close friendship with a Muslim girl in Reception, and they were just mad about each other. I was suggesting getting together for months, and we always got very polite and gentle but definite rebuffs.
I twigged one day, when I had our dopey springer spaniel with us and we met the girl and her mum in the street. Again, she was v subtle about it, but it was obvs she didn't want to talk to us for too long as the dog was there. The family knew we had the dog already, but only rarely saw her with us. Me being me, a few days later, I asked if the dog was a prob....could we put her in another room when her DD visited, and so on? I got a very round-about-the-houses answer (in retrospect I shouldn't have asked, as it put her on the spot) that kinda revealed that the dog was an issue.
Still on friendly terms with the mum, and we'll always stop for a quick natter, but sadly we couldn't take things further.
So.....finally I'll get to my point. If you don't mind dogs, maybe drop a few hints to dog-owning parents. You never know....people may not want to offend you by inviting you and your DS to a play date because they have a hound.
The parties will take care of themselves before much longer, I should imagine, and you can attend them and do a bit of "captive audience" schmoozing!
Just read this back, and it looks a bit bonkers, but it might be something to bear in mind.
Congrats on the new baby, btw!