IMO you are rationalizing too much because, as you said, you are being paranoid and risk averse.

I moved from a third world country to the UK (London) and at some point I had similar concerns as you have now.

At the end of the day, living means taking risks everyday no matter where you are. My final conclusion was that if I didn't move I would regret not taking the risk, I wanted to know how it feels to live where I live today. I wanted to live an adventure rather than staying on my home country and developing regret.

I don't know you but just reading through your post it seems that you want to do it but fear is holding you back. Are your fears unreasonable? Probably not. Should they dictate what you do with your life? Absolutely not.

It's also fine if you decide to stay, just don't allow this to become a source of regret in your life, be in peace with whatever you choose.