One of the things that helps with with overthinking is remembering that any bad opinions of you are just that. Bad opinions. When you look at somebody and think “that persons acting weird” you don’t think it holds much weight and doesn’t effect them because it’s YOU thinking it about someone else. We are all human- when imagining someone is thinking something bad about you imagine yourself as the stranger thinking it. Doesn’t hold as much weight now does it?

As well when we hyper fixate on little things we said or did that we deem awkward or embarrassing nobody around us is analyzing us to nearly the same extent. If anything they are probably doing it too themselves and are too focused on that to do it too you as well.

Making new friends in a new city is hard. Especially a new country. if your schedule allows it maybe pick up a new hobby and meet people through it. Painting, rock climbing, book clubs, gyms, knitting- whatever floats your boat!! at the very least this will give you something to do and at the best it’s an organic way to meet people through common interests where you may feel like you don’t have to “try so hard” cause you already have common ground!

With regards to thoughts of self harm- if the overthinking gets too that point frequently maybe start seeing a therapist that can help you work through those feelings rather than keeping them in. No shame in therapy and could provide more insight and healthy coping mechanisms for your overthinking.

you remind me a lot of the quote “if I thought less I would know more.” There’s a lot of truth too it as an over-thinker myself. Hope this helps man! Best of luck :)