Forums, find forums for things you like, post stuff, get chatting to people, talk about anything. It's a but clichéd but building up a bit of an online comunuty of "friends" to chat with especially in the late evenings when your kids have gone to bed.
Stack exchange, quora, discuss etc is a good q&a site answer and comment on questions.
Here is another good one DM people get chatting.
.DM people in twitter, join Facebook groups Dating sites god they are hard work and there is too much expectation, if you just want a grown-up conversation.
I know what I'm saying is very internet focused but it's intent was as a medium of communication.
Again a but trite, go to the same shops cafes boozers at the same time same day. People are creatures of habit and the work a regular schedule. I can pass 5-10 mind chatting with the woman at the cigarette counter at Tesco's in the morning
The young woman at my local coffee shop, I go in 2-3 times a week for a cuppa over the months we've got chatting.
Your barber 20 mins in the chair getting a trim have a natter
School and daycare, get there a bit early batter with the teachers at the gate name appointments to see the principle and welfare teacher frequently.
This bit will sound aweful, even your GP. I'm concerned about my MH so I go monthly just to chat over how I'm doing and if I'm ok. I see the same GP everything, she's lovely, we chat about school, our kids, the economy or relationships, exercise and she's only a few years younger than me and drop dead gorgeous. That's possibly transference and could be creepy if I wasn't self aware but I come away from seeing her feeling better because of the human interaction.
I do understand how you feel and I do all the above stuff, it's got to the point where on the occasional evening I think, I don't want to "talk" to anyone.
I takes a bit of effort and you have to over come the god I'm embarrassed feeling, but you can do it.
BTW single dad 50, 2 dds 13&10, 2 ddogs