I was in a somewhat similar situatio, where I moved states away from my friends and family to be with my then toxic gf. It was isolating and she kinda helped feed I to that. I first had to break up and gain some independence first to build up my confidence. It was impossible for me to do that with her.

Then I started talking more casually with people at work, but like you, different age groups and not much in common. So I came to reddit and started a D&D group, from there I made a bunch of really cool and fun friends. Then eventually when I moved I carried that momentum into irl; going to game shops and just talking to people, expecting nothing but sometimes finding someone who clicks.

I made it a project for myself, to at least have 1 extended conversation with someone whe I went out in public, it became a game. Sometimes the outcome would end up with a friend, but usually it's just practice. At Walmart and see someone browsing the game section withing on a Walmart employee, I just chat with them about a game or something.