I think the people saying you don't want another child are being deliberately dim. Having a child does not automatically mean you don't deserve and can't have a life outside of children.
Where I do think you are wrong is that assuming that because you don't have a social life sorted out, your husband should sacrifice his. It's on you to sort out what you want to do with your life- I know it's hard, but nobody else can do it for you. It's literally your problem to solve.
In your situation, I joined Peanut (a mum app) and made a couple more local friends, with kids similar ages. But, specifically, I started chatting with those who listed interests that were not all child related- who said they liked going dancing, eating out, a glass of wine chatting with friends. The mum I clicked with is very sociable, and we now see each other regularly both with and without the kids- it was awkward at first, but after visit 2 it eased, and we're good friends.
Secondly, I joined a book club. There are lots of people there who don't know each other, and it's not a highbrow one at all. We meet once a month in the pub, but there's no expectation to drink- have something if you want something. We sit, chat for half an hour about the book, and then just have a nice hour sitting together. Gradually it's grown, so there's now about 15-18 of us, we invite along any friends who are in your position basically! And this was set up from nothing by my sociable peanut mum friend- she had looked on Facebook for a local group, didn't find one that suited, so put up in a local facebook group that she was planning on starting one, and individual people joined her. We all didn't know each other a year ago, but there's some lovely, bright, funny women there.