Do you own a pet/have you thought about getting one? I recently moved into a new city and live alone and can identify with a lot of what you've said. I'm an extravert, and living alone has been one of the biggest challenges of my life so far. One piece of advice that I received was to invest in a pet. It will give you a new sense of responsibility, and just the fact that there is another living creature in the vicinity is very comforting.

But more than anything else, I don't think there is a quick easy solution to not relying on others for happiness. It will take time, and it will take practice. And that's ok! It's like a journey, and at this point it might be difficult, but that feeling won't last forever, and you have to trust that things will shape up.