Sorry. It's hard, isn't it?
Is there anyone you work with that could be a friend? I know a bit how you feel, we moved to another country a year ago and I have made one good friend who is moving away this month
I have made a couple of friends through a facebook group for New Zealanders who live in Norway, but other than being from NZ we don't have that much in common. I still catch up with them quite a bit and try to make it work but it's not like with my good friends, where it's effortless to spend time together.
I am good friends with both my SILs, have you got family nearby, that you get on with? I know there's not much (any!) spare time when you're a mum and working full time, but do you have any hobbies? That's a good way to make friends, it only has to be one night a week or something.
Maybe nobody invites you out because you never invite them out? Have you tried asking someone if they want to catch up for a coffee/playdate with the babes/movie/girly night? I think a lot of adults find it hard to make new friends too, people take pretty well to being invited out for a coffee or whatever, in my experience at least! I've started asking mums with children in my daughter's kindergarten and they don't say no, they're often feeling lonely too. One of them I've clicked quite well with and our daughters adore and entertain eachother.
As for bridesmaids, I'm getting married next year, in my new country with none of my old friends and I plan on asking my two nieces (5 & 10 yrs old) and probably my daughter too. I think they'll be the cutest bridesmaids I could have
Sorry this was long, I understand your situation and it is very hard, I've found it hard too. Bnb is always a good place for support
ETA: Does your OH have any friends with gfs/wives? My OH has one friend whose wife is so lovely, I'd definitely want to spend more time with her if they lived a bit closer to us.