Welcome to the forums! Many of us struggle with anxiety so I hope this forums makes you feel less alone with what you're going through.
I have anxiety too and it's largely under control now. I manage it by doing mindfulness exercises and being more aware of the way my body is feeling. For instance, when I start feeling my typical symptoms of anxiety coming on, I actively try to do more relaxation exercises and try to address the event in my life that's causing the anxiety (if I can pinpoint it). Talking to people during these times help too since you can get advice/see things from another perspective.
With regards to making major life changes, it may be easier for you to take it step by step. Since you're used to being alone, you may find yourself just retreating to your home instead of making friends as you intended (that was what happened to me when I moved). Why not start now by joining community groups or volunteering? That way, you'll get into the habit of having people around you.
Anxiety is most definitely not a sign of weakness. In fact, facing it and trying to control it is an incredibly strong thing to do! I'm glad to that you feel you've come far, it's truly an achievement.