I've had RA for right at 2 years now (diagnosed March 2011). You're not alone in your fears. I really struggled with that, especially the first 6 months. Here are a few things I've learned:
1. You have just as much of a chance to be hit by a bus tomorrow as the next person, lol. Meaning, nobody knows what tomorrow holds. I get really scared when I think about what life is going to look like in 10 years so I focus on what I can do today. That was a really big deal when I first got diagnosed. I actually wrote down all of the positive things I could think of that day so I could see the things
I could still do and then tried to focus on those. As time went on and my RA got better and better controlled I was able to do more.
2. Take the pain meds if you need them. If you wait until the pain is unbearable chances are they pain meds won't work well and that just creates even more of a problem. I know what you mean about not wanting to take them now but I think pain free days really help with the anxiety as well. I have some days where my pain isn't all that bad but I'm on my feet all day at work and if my knees are a little sore I really notice it and I can't stop thinking about it and then I get anxious and overwhelmed. When I take the Aleve most if not all of my pain goes away and I can forget that I was having pain and my anxiety goes away.
You will be able to cope better as time goes on. It's very overwhelming at first but things get better! Try to remember that a lot of what you read on the internet may have been sensationalized or is the stand out case that didn't have a good outcome. Most people do very well these days. There are lots of options out there. I hope you're able to find a doctor that works better for you! Take things one day and one step at a time and you'll do well!